Trying to keep the thread alive. Still having issues, even after camoto’s fix. Reset both ap decos with “downgrade” but it seems the main one is still having issues. Problem is, resetting main wipes all settings which is a major pain for me. When can we expect a new firmware from the company. Really getting annoying!

I’m still running with 5Ghz switched off (beam forming and fast roaming are both on) and everything has been stable for weeks.

Given reports here and elsewhere I’m not going to apply the Beta or downgrade, will stick where I am until a fix comes out and will then try enabling 5Ghz again.

I'm still having issues too. The system has worked perfectly untill the last update. I have disabled 5GHz and most of the problems are now gone but not all of them. Anyway I would like to use 5GHz so if anyone from the TP-Link support team reads this, please fix this ASAP.

And still there is no solution from TP-link! These problems have been going on for a while now. It is really unacceptable that TP-link doesn't give any response and that switching off 5 GHz is the only option to have internet!

Thank you. I switched of 5GHz and it seems it's a work around, but my connection is very slow now :-( 

I'm getting back to Asus. I've had an Asus AC-66U for several years without any problems. I have these Deco M5 for just 2 months now and experiencing only problems without a proper solution! 

Mine's still going fine, latest firmware, 2.4 & 5ghz both on.

Possible solution:

I just recieved my new deco m5's (ordered before the update fiasco).  I plugged in the new ones and they "demanded" an update.  I reluctantly took the update for each and they went to the 1.24 firmware.  Now when I check the app, it tells me all deco's are up to date with firmware 1..24.  No more mesh switch or beamforming options, both the 5Ghz/2.4Ghz are on, and everything seems to be back to normal (no more dropouts, etc.).  Maybe resetting the ap's will allow a firmware update across all deco's and solve the problem?  Mine seemed to force the downgrade of all my other deco's.  Not a proper fix, but I hope this helps. 

Three weeks and still no fix for this problem. How hard can it be? Wonder if it would be possible to do a warranty claim?

Today I tried the fix from TP-Link Deco for the second situation (listed under "incorrect password"). Looks like an improvement: no complaints from my users at home until now.