Some new android's have option to set DNS over wifi network.

in some cases if you set "use private dns" you got internet connection but no traffic. Just disable private DNS.

But So, support changed the channel to 6 and width to 20Mhz, (I changed the ISP to channel 1, always 20Mhz) and the issue is still there.

The issue is seen while doing pings from my laptop (on same wifi as the nokia 2.2) that suddently all start to fail. After some time the video complains lack of connectivity, and some time after, the wifi shows no internet. And while the pings are ongoing, after some time (without disable/enable or wifi on the nokia), they seem to start again. Strange enough, when I leave the nokia 2.2 to "sleep", the pings do not seem to fail.

But this time I did the exact same test and pings with a nokia 4.2 (also android one 9 pie but more powerfull/different hardware), and not only I did not have a single failed ping but the response times were way better.

And finally connected both laptop and nokia 2.2 to the ISP router and did the same test, and here while I do see once in while a failed ping, the next is always a good one, so there is no accumulation of failued pings, so the connectivity keeps ongoing and there is no failure.

I see that the deco is quite chatty, is it possible that the network timings are too agressive (there are some issues pointed out on the openwrt foruns related to this) and this causes slower CPU mobile phones to have more dificulty to keep up and thus tend to fail more (probably the dns requests the android does to check if the wifi has internet connectivity), thus causing them to think they have no internet connectivity?

I remember this one and I disabled it, but compariring the nokia 4.2 to 2.2, saw that the private DNS on the 4.2 is set to automatic (that apparently then shows up "activated").

So I changed the nokia 2.2 to automatic and did the video test and it seemed that the ping failures started a bit later, but eventually led to to the failure of the video play and complain of lack of connectivity.

@VCL 

"I remember this one and I disabled it, but compariring the nokia 4.2 to 2.2, saw that the private DNS on the 4.2 is set to automatic (that apparently then shows up "activated")."

Change from automatic to Off. I got this problem end when turn off.

@ivy Maybe it was a bit confused but this was disabled all the time on the nokia 2.2 off.

But since the nokia 4.2 (that has no wifi issues) had it automatic, I decided to also test the same on the nokia 2.2: made no difference.

In resume, the nokia 2.2 with disabled or automatic has wifi issues (and the nokia 4.2, automatic or disabled works fine).

@Kevin_Z 

The feedback I post here is after work done with support or tests done by me and support informed of those, so they know.

Last time I also mentioned that another portuguese (coincidence?) had the same issues and they asked for the forum threads, information I provided yesterday.

I am sure support has or will check both threads and take notice of the devices affected, now that it is confirmed that this happens with multiple devices.  

@Kevin_Z 

Just had a teamviewer session with somebody from tp-link R&D while doing the usual tests (and second deco turned off) AND the issue is no longer there, the videos played fine and we saw no ping failures at all. Nothing was changed BUT this weekend the nokia 2.2 received the android 9 [security] patch of october! So, it seems there was fix somehow on it that casued the issue to go away and, at least on all my devices now, I no longer have anuy wifi issues.

Kudos to tp-link again, great support, I am really happy, l enjoyed my wr1043nd's, I am sure I will enjoy my deco M4R as well, even more now that I know they run openwrt, my favorite router firmware :)

I'm having very similar issues since replacing my WiFi with two Deco M4Rs in router mode.  I'm seeing 2 Amazon Fire 7 tablets and various Echo's and Echo dots dropping off.  

The Echos will eventually recover automatically, but the Fire 7 tablets need to have WiFi turned off and back on again.

The tablets show as connected, but I am no longer able to ping their IP addresses until WiFi is turned off and on again.

We have a Fire 8 HD which doesn't seem to lose internet at all, and the Fire TV sticks also seem OK.

The M4 are v1 units.  I might try a complete reset of the M4s and if no improvement I'll send them back.

@VCL 

Well, when I did last tests with tp-link support, we did not had any issue...

Today, to answer an email to nokia (to whom I also reported the issue), I decided to test again and found out that the issue is still there: I started playing a live concert on the youtube app (like last time) and after 6 minutes or so, got the "no network" message :(

Nothing changed in the setup/config but the decos rebooted and now seem to use channel 4, and the nokias 2.2 in the meantime received the november update (october seemed ok, november not, but the last test could just have been that very few devices where plugged in to the decos, no idea why I get the issue again).

And this is what I get from pinging it from the router:

--- 192.168.0.107 ping statistics ---

232 packets transmitted, 114 packets received, 50% packet loss  <<< 50% lost !?

round-trip min/avg/max = 1.256/3332.161/22212.438 ms