@pman2022 

On the router DHCP settings, change the lease time to the maximum you can use.

  @Somnus - Thanks for the suggestion.  I had set it to the max as part of my debugging

  @pman2022 "  I think what was happening is that when the two CPE210s are first booted up they work fine as APs until they find each other and depending on which one becomes the AP and which one becomes the client one side continues to work and the other is there but you can't connect to the Internet thru it.  That would explain why one CPE210 stopped working as an AP but the other was fine. "

Unless that is some special feature of the CPE210, that is not what is happening. They do not go into this configuration on their own. You have to manually scan for the other, select it and enter the password (if set).

" The AP do NOT get an IP address as they are merely a pass through to the HUB and then the Verizon 5G router which assigns the IP addresses. "

This is also not possible. They have to have network information either automatically assigned or manually assigned. It sounds to me that you have a IP address conflict or misconfiguration.

I think by default they devices are set to a static IP of 192.168.0.254. If you did not change this to dynamic, so they could be assigned appropriate IP addresses, or set the addresses and other information manually, then you potentially have two devices with the same IP address.

  @RickJamesBish - Thank you for your reply.  I wanted two Access Points to cover two areas outside my house (front and back).  Since I found out from TP-Link support the CPE210s were not the recommended devices to use as an Access Point, I purchased an EAP225 and installed it yesterday to replace one of the CPE210s.  I did this based on the now false assumption that the two CPE210s were the cause of the problem.  That did not solve the problem as you indicated/predicted.  I do like the EAP225 user interface and wish I had purchased 2 of these to begin with and I may replace the 2nd CPE210 in the future with an EAP225.

But back to the problem.

With now one CPE210 as an Access Point and one EAP225 as an Access Point it worked for awhile.  But, over night, I still ran into the problem which does point to an IP Address conflict as you indicated.  The Verizon 5G router is configured as the DHCP server and I don't have any static IP addresses assigned. So I'm not sure how to debug this from here.  Does this look like a router issue?

I broke the cardinal rule when doing all this of changing two things in my network at the same time.  At the time of adding the 2nd CPE210, I also was switching from STARLINK to the Verizon 5G router (faster and cheaper than STARLINK).  I had STARLINK since Feb. 2020 and the single CPE210 as an Access Point were working for two years.  When  my IP address conflict first happened I switched back to STARLINK and didn't see the problem but for some reason I didn't assume it could be the Verizon 5G router.  I should have stayed on STARLINK for more than a day but I didn't.  Since I had also added the 2nd CPE210 at this time, I focused on it.  As you pointed out, I noticed that the CPE units both had the address 192.168.0.254 so I changed one of them to 192.168.0.253 and thought I had fixed it.  A day later the problem returned so that was not the problem.  So I continued down my rat hole of believing the two CPE210s were in conflict and purchased the EAP225 Access Point.  Now that I have gotten that false idea out of my head, I'm back to my problem.

I still have STARLINK for one more month so I can switch back and see if that fixes the problem.  I believe that would suggest that the new Verizon 5G router has a DHCP problem?  Before doing that I wanted to try one more thing on the Verizon 5G router where I changed the "Address lease time" from the default 24 hours to 1 hour to see if this would maybe work around the problem.  I really want to keep my Verizon 5G router for cost and speed improvements.  I don't know if there is any negative consequences of reducing the lease time?  If that works for a couple of days, I will still try switching back to STARLINK since I have it for another month.

My STARLINK solution (the STARLINK router did the DHCP) had an extra level of complexity in that I wasn't using it for WiFi as I had a PLUME mesh network which did the WiFi for the house.  The 50 WiFi devices connected to my PLUME mesh network  were working so I didn't want to mess with it (here I did observe the rule of changing one thing at a time).  On the way to debugging my switch to Verizon 5G I tried getting rid of my PLUME WiFi network since the Verizon 5G seemed to have a very strong WiFi signal throughout the house (4000 sq.ft. two story).  I didn't check at the time if the STARLINK router's WiFi could also cover the whole house, and I will when I switch back.  I also didn't know if keeping my 50 WiFi devices, which were configured for my PLUME network, would be as easy as configuring my new Verizon 5G routers WiFi with the same SSID (PLUME) and password.  So I changed my Verizon 5G router WiFi SSID to PLUME and the PLUME password, and all 50 devices worked. I had thought that going to a new router might be as easy as just keeping the last router's SSID and password but I had never tried it.  I thought (and it might still be true) that devices MAC addresses may play a role in joining a network.  For my devices that doesn't appear to be the case.  I've had PLUME since 2016 and it's worked well but I'm not using their newest hardware and the Verizon 5G actually got better WiFi speeds in most of the house.  The two dead areas the the Verizon 5G WiFi couldn't reach ironically are near the two outdoor Access Points so I could use those to fill in.  So to reduce complexity I would like to use the single Verizon 5G router and two TP-Link access points for outside.

So I will run with my Verizon 5G router supplying DHCP with a "Address release time" of 1 hour (changed from the default of 24 hours) with the Verizon 5G router supplying WiFi using my old PLUME"s SSID and the old PLUME password to keep my 50 WiFi devices happy.  If that works for say a week, I will switch back to STARLINK router with it supplying DHCP and configure the STARLINK to provide WiFi with the PLUME SSID and password (hopefully it is strong enough).  I will also check if STARLINK has an "Address release time" setting and if so what it is set to.   In both configurations I will have removed my old PLUME mesh network to simplfying things.  I'll post back with what I find. Or if you have any better ideas??

Update 2/28/2023 - So my issue is solved but because I tried multiple things at the same time it's hard to say which one fixed things.  I suspect that my problem was that the Verizon 5G router comes set to use IP address pool 192.168.0.2 to 192.168.0.254 and the top range needs to be 192.168.0.249 so it would not conflict with the CPEs which use the last address 192.168.0.254.  I changed my address pool top range to 192.168.0.249.  Along the way I purchased two TP-Link EAP225 to replace the CPE which was recommended by TP-Link support as a better match for what I needed.  I like the EAP225 App. much better so the extra purchase doesn't bother me.

  @pman2022 Not knowing how you have the CPE and AP set is a big drawback in figuring out the issue. Take a screen shot of your config and post here. For example this is my CPE connected in client mode to a EAP610 Outdoor.  The IP address of the CPE is on the same subnet as the router (gateway)? 

  @RickJamesBish I'll attach a diagram of my network, a screen shot of the NETWORK tab of the CPE210 and a screen shot of the EAP225 AP.  I now have only 1 CPE210 and I used the Quick Setup to set it up as an AP.

  @pman2022 first thing that is evident is you do not have the gateway set in the CPE. 

Look in your routers DHCP settings and find the IP Range. It may be labeled as IP address range or pool. See image below.

Pick two IP addresses just outside the range. For example if the range is set to 192.168.0.100 - 192.168.0.249,  enter 192.168.0.250 and 192.168.0.251 as the static IP addresses for your CPE and EAP.

On the CPE210 leave as static as you have shown.

Enter 192.168.0.250  (example / may be different because I don't know what range your router is using)

Enter 192.168.0.1 as the gateway.

Enter 198.244.174.135 as primary DNS and if you can find the secondary DNS in your routers settings, enter it or leave blank.

On the EAP225 leave or set as static.

Enter 192.168.0.251  (example / may be different because I don't know what range your router is using)

Enter 192.168.0.1 as the gateway.

Enter 198.244.174.135 as primary DNS and if you can find the secondary DNS in your routers settings, enter it or leave blank.

See image below for IP range set by router. It may be labeld as POOL or RANGE.

Yours is going to be a 192.168.0.xxx, not a 192.168.1.x like the example  

  @pman2022  For the CPE210 I set the gateway IP to 192.168.0.1 and the primary DNS to 198.244.174.135 and the secondary DNS to 198.244.173.135 (from the router).  The CPE210 already had an IP assigned as 192.168.0.254.  The router had an address range of 192.168.0.2 to 192.168.0.254 so I changed the ending address to 192.168.0.249 so the CPE address is above that.  The EAP225 didn't have a place to assign an IP address and DHCP assigned it 192.168.0.162 .  So I will run with this for awhile.

Thanks!

  @pman2022  Yes the CPE210 is set to static and by default has an IP address of 254.  You don't have to but I would change the static on it to 250, 251, 253..  Reason being that 254 is a very common static IP address that is set to new devices. If you add something new you may immediately run into IP address conflict. If you know you are not going to add any hardware later then you will probably be ok leaving it.

I would also look through the EAP225 settings. It sounds like it is being assigned correctly but I would still verify it. There should be a place that shows you IP address, gateway and dns. It can be assigned static but if its working correctly and has the correct gateway and dns, then no real need.

  @RickJamesBish Thanks for the tip