@Bsworld 

The first thing we always recommend is to check for firmware updates, but you have already done that.  The next few items would be network related.  First try hitting the 'network optimization' button and see if that helps.  If not your next step would be to turn off Fast Roam.  This typically helps stationary devices like desktops, TVs and smart speakers, devices that don't move.  Fast Roam can be helpful for moving clients but can also affect ones that don't move.  Last actions would be hardware related.  Relocate the remote nodes to try and create more overlap.  Or in the app designate an different unit as the main unit and then swap locations with the current main. 

@Carl 

OK, in order:

1.  Have tried the optimization option any time it has suggested it can/would help.  No (noticeable) improvement on the issue.

2.  I have opted to leave (overall) the fast roam option on/active and instead have gone in to the items that are more stationary and de-select the roam for them (thereby really only leaving our phones, tablets etc. to roam).  One would think that would prevent me from having phone issues AND the non-roaming desktop as well, but no.

3. I have shifted the nodes around a bit (as much as I can) but feel I truly have a lot of overlap as it sits at the moment.  That said the troubles with my phone can happen when I am in the room directly below from the main Deco unit, or when I am in the same room with it!

I also should mention I have made no other meaningful/significant changes/additions/etc. to my network between when things worked great and now. 

I appreciate the ideas/suggestions but have tried to be very thorough in my troubleshooting things before coming for help.  What now?

@Bsworld 

1.  Sounds good. 

2. I would still try to disable Fast Roam as a test.  This FAQ explains why it can cause issues to devices.  Disabling Roaming on the stationary devices would not address the concern in the FAQ because its protocol based and not device.  Disabling roam on a stationary device only stops the device from jumping to a different node.   

3.  Have you tried to switch the primary node with one of the remote nodes?  If not I would say try that.  If you do just make sure you desginate the new node as primary or main in the Deco app otherwise you may have connectivity issues.  For the distance between nodes, would you say you are within 25-30 feet of each other?

If none of the above acutally helps let me know.  @Kevin_Z  Have you noticed any issues with the Deco X90 on your end that cause intermittent connectivity?

@Carl 

Need to clarify/correct something...  I never had 'Fast Roaming' enabled, I just was confusing that with the 'mesh' setting on each of my devices.  For the static location devices (desktop, smart spotlight, etc.) I have the mesh switched off but have maintained it on the more mobile devices (my phones, tablets, etc.).

I'm not fully sure how to make one of the secondary Deco units become the main node?

No way are my Deco units just 25-30 feet apart from one another.  My main unit is upstairs in an office, the others are located 1. X20 in the upper portion of the garage (maybe 25 feet away through 2-3 walls), 2. X90 in the laundry room (some 50 feet away with 5-6 walls in between), and 3. X20 located outside in a fiberglass box (line of sight out a window from the main X90 but likely 100 feet away).

Wondering if you see (or are able) to monitor the continuity of my network connection at all?

Thank you again for the help!

@Bsworld  Hi, I have had exactly the same issue with my X20 system. Worked for 6 months and now dropping frequently. Works perfectly through the ethernet cable, but WIFI is broken. I have completed all of the trouble shooting and have also had a senior engineer attempt to resolve the dropping out / password authentification issue to no avail.

There is something broken in the firmware update or a hardware issue. Maybe the firmware update if more customers are experiencing the same problem. 

I have wasted hours over the past fortnight trying to resolve this.

  @TP-Link 

'For your case, could you please log into the web UI, and save a picture of the network layout about the Deco units?'

     How do I do that? 

'By the way, did all the satellite units wirelessly connect to each other?'

     Yes, they did.

'May I know what are the models and operating systems of the mobile devices that had intermittent drops/fails?'

     Two Samsung Galaxy S20+ mobile phones (now running Android 12 - updated last evening), and my Notion home monitoring system (tracks open/closed doors, temps, etc.).  I am sure other devices are also bouncing, those are just the ones that get A) used the most (phones) and B) speak up for themselves when the network fails.

'And have you noticed any error message when they are disconnected, like “Failed to Authenticate the Password” which is what PeachyP run through?'

     No.  Nothing.  Typically it's just me noticing the HTML portion or photo in an email doesn't load, or I click on a link in an email/text and can't get to it on the web.

Later, I would like to forward your case to the senior engineers as well, and please check whether you could get an email from us.

     I see I received an email notifying me of a support ticket being filed, what next?