@pdamasco  I am having a similar issue with the latest firmware version.  have you fix the issue?

@Akuini I actually have a call and remote support session setup with one of TP-Link's engineers on Sunday so that they can see the behavior.  I have a temporary work around that seems to work until you reboot your router, at lease for me.

Please be aware that I know the following doesn't make sense but it works...

Before you begin please ensure that "AP Isolation" disabled on Advanced > System Tools > System Parameters > "AP Isolation Feature"

1. Make sure you have "Smart Connect" enabled

2. Navigate to the advanced settings

3. Go to guest network

4. Togle the option labeled "allow guests to access each other" (doesn't natter whether it is on or off you just have to change the setting...)

5. Once you switch the setting select save

6. Reboot your router and wait about 4-5 minutes for all of your devices to connect then check things like ChromeCast device availability, Apple Bonjour/AirPlay, and see if things like your printer can receive pings from devices on opposite frequency bands.

If after doing the above you still cannot ping devices accross wifi bands go back and toggle the feature again, reboot, and repeat tests until you have success.  You may have to hard reset the router as well.  After a hard reset and following these steps above my devices can communicate across bands but if I reboot the router many times I have the issue all over again and have to do what I describe above.

Please let me know if this helps you 

@pdamasco did you get any resolution on the issues. Seems to be a bug with the two wireless system 2.4 and 5 they stop communicating between devices. Only resolution I have found to is to run 2.4 only then everything works as all devices are on the same wireless. 

@Meagain I have not as I am still waiting on their call/remote support. Did you try the suggestion in my previous post to the other user?  It has been working for over a week after doing what I suggested in my previous post. It is extremely frustrating though as this is a fundamental function of a router and at like $300 this shouldn't be an issue at all. If my previously recommended fix doesn't work for you it may be a good idea to submit a support ticket to TP-Link. If enough users report the same issue chances are they will have a better chance of solving it and would have more reason to look into it.

Edit: It started doing the same thing tonight after working for several days before........  Hopefully they call me for this remote support session.

@Meagain I just got off the remote session with the TP-Link engineer and he was able to confirm that there is something that needs to be changed at a firmware level. They will be working with me over the next few days/weeks to get a beta firmware to me for testing.  It is likely that an official firmware release will take several weeks as they need to test any upgrades extensively before releasing them as official builds/releases.  He was however able to see the issue in realtime and believes he knows what is causing it so fingers crossed the beta firmware they provide later will fix this 

@pdamasco amazing work my good sir! I have been loving everything else about my AX6000 other than my printing not wanting to work and I was getting close to pulling an Office Space on my printer :)

I will hold fast and pray a new firmware will resolve the issue. Thanks for your dedication and hard work on this effort, much appreciated!

@pdamasco Just adding a +1 here; I'm seeing a similar issue that I believe is probably from the same root cause. I cannot get Sonos speakers to reliably be seen by the Sonos app with Smart Connect on (despite the router's setup page confirming they're all in the client list and connected successfully). I thought at first that this might be a Sonos-specific bug/incompatibility with the router, but then realized that Sonos are the only devices on my network limited to only 2.4ghz, and the mobile devices running the Sonos app are on 5ghz. When I turn off Smart Connect and manually set the 2.4ghz channel, the speakers seem to work reliably (for whatever reason, I have the same issue when 2.4ghz channel is set to Auto, perhaps just router doing a poor job of choosing the channel though).

I know you mentioned that your issue is not Smart Connect-related, but maybe something about Smart Connect is also causing the issues communicating between the two bands or inadvertently turning on isolation? I do not have to completely disable one band or the other to get the 2.4ghz speakers to be recognized by the app on 5ghz.

This is all super frustrating since I replaced a 5-7 yr old router with this very expensive one hoping for better performance, but actually it just introduced this new issue for very basic functionality.

@Eab6287 Well I've gone through three remote support sessions with them now all over an hour and the firmware R&D team is working on it. They are seeing the behavior but from what I can tell are having trouble reproducing it in the lab. They can see the behavior on my unit and have several ideas about what might be causing the issue but I don't have a working beta build yet.  It's very strange because routing is fundamental to a router but something deep in the code must be borked for this to be occuring and making it so difficult for them to track down.

Hi Everyone,

I just wanted to give a quick update on this. I was able to work this out with TP-link engineers about a week and a half ago. The BETA bios they supplied fixed the issue and they are working on baking the fix into the next official release. I am not sure exactly when that is coming but I can tell you we got it fixed. I'm not sure if I'm allowed to post the BETA here but I am going to @Tony in the hopes that he can confirm if this is allowed by the community guide lines. If it is I will try to post the link/download here.

I also want to say thank you @Tony. The whole TP-link engineering and firmware team was very nice to work with and were very accomodating. When this issue came up I was very upset especially because the AX6000 isn't a cheap device. I was worried that the issue would go unresolved and I'd be stuck with a very pricy ineffective router. The TP-link support staff changed my mind and the fact that they are willing to work directly with users is fantastic. I've never seen companies that had Firmware developers and senior engineers interface with customers. It is RARE and I very much appreciate that TP-Link provides this level of support.

I provide IT support and administer systems at a very large University so I know what it is like to be on the other side providing as much information and assistance to the customer as possible. Thank you all for your work and dedication to the products and customer satisfaction. When I need another upgrade in a few years I have a feeling I will stick with TP-Link due to the support alone.