@David-TP I have the exact same issue. I have two Deco XE75 Pro working as access points. I also use Pihole as DNS server and ER605 as main router.

 

Main Deco has same error messages for NTP, same incorrect time, it never syncs after power offs, reboots, etc. Additionally I cannot check for update in the app.

 

How is this problem solved?

  @pajtaz for me the answer was a beta firmware update provided by support. 

pajtaz wrote

  @David-TP I have the exact same issue. I have two Deco XE75 Pro working as access points. I also use Pihole as DNS server and ER605 as main router.

 

Main Deco has same error messages for NTP, same incorrect time, it never syncs after power offs, reboots, etc. Additionally I cannot check for update in the app.

 

How is this problem solved?

 

Thanks. Actually, this is crazy, I think I have "solved" the issue. I will list it in the next post.

I was losing my mind with the time issue so I decided to take out the 3rd Deco XE75 Pro from the 3-pack I got and set it up as the main Deco. I purchased the 3-pack for the upcoming move to a new house and I was only testing the system with 2 units. Anyway, after some time I setup the 3rd Deco as the main Deco and move the old main Deco with the time issue to a new location to see if it can be fixed. After doing all kinds of reboots, power on/offs, firmware downgrades/upgrades, nothing helped with the time issue of the old main Deco.

 

I am tracking a different issue with the same Deco XE75 Pro system. In that post I am having an issue connecting to a specific 5GHz device after some random amount of time (days, weeks, not hours). In that post I also mentioned the issue with time.

 

Now I just did something that made me think the whole issue is somehow router related. I use TP-Link ER605 as my router and I assign static IP addresses for almost all hardware in the local network, both wired and wireless. I assigned static IP addresses to the 3 Decos. Before I had the Decos, I had TP-Link WDR3600 wireless router which I used only as an access point. I used to assign a static IP address to that device. That device is no longer on the network, I removed it/stored it after getting the Deco XE75 Pro 3-pack.

 

Well guess what? The entire time I was having this issue with time and with this 5GHz device connection, I had assigned the same IP address for the old main Deco unit as that WDR3600! It should not matter but ... just now I assigned a different static IP address to the troublesome old main Deco unit. Guess what? Time issue was fixed.

 

Now it makes me think - what in the world is going on with ER605 and static IP assignment that is causing this issue? Is there some sort of cache somewhere that is creating this issue? All I know is that as soon as I changed the static IP to something other than what is was for that WDR3600, the issue went away.

 

Any idea? I will keep track of the other issue I have with 5GHz device, it very well could be related to the same thing.