UPDATE:

I got a chance to test on some other devices.  I made the silly mistake of assuming I'd narrowed it down to the BE10000 environment and got a chance to test on several different devices, including two different Windows boxes.  In both cases, the Windows boxes are fine on both networks and Teams and M365 run w/ no problems.  I've confirmed it's still a problem on my work device, a Mac mini and my team and I are testing to see if one of the office settings in place to the standard device management agents are causing this.  

Thanks for any who reviewed.

___________________________________________________________________________________________________________________________

I have two seperate wifi environments in my home, one running off of a BE10000 (3 BE63's) and the other an ACE5400 (3 XE75 Pro's).

Both have the same settings.

Both are plugged into a common gateway router, a GL-iNet Flint 2 with fault tolerance enabled to map between my primary ISP and a 5G backup.  None of the security features available on the Flint 2 are enabled, it's currently only being used for fault tolerance between ISP's.  It's own WiFi is currently disabled.

About a month ago, sites I use for work, including M365 and numours web sites, started becoming inconsistent or completely unavailable.  The first alert was when using Microsof Teams, I get the notice i'm no longer connected to the Internet.  Certain other sites, including Netflix and (as I type this) YouTube TV are streaming just fine w/ no problems.  Switching to the ACE5400 network fixes the problem.  I waited until the recent firmware update but this has not resolved the problem.

I've run Network Optimization to make sure the two networks are on different channels.  Both reported success with configuration and 2.4, 5 and 6 Ghz networks are all seperate from each other and the one neighbor who's close enough for their signal to bleed over.

AP's are at least 12 feet from each other, but again, all are operating on different channels.

They're configured to reboot nightly.

DHCP from the Flint 2 passes to the TP-Link's itself as DNS which it gets from my ISP.  I've tried changing this to Google's and OpenDNS but no change.

DHCP to clients on both networks use OpenDNS IP's.  I've also changed this to use the ISP's and Google's to no effect.

I've not configured VPN nor any of the security features on either network.

I'm only getting IPv4 from my primary ISP and that's all I'm using internally.

There are no overlapping IP ranges.  Shouldn't be an issue anyway, but I did check that.

There was no warning or settings changes made immidiately before this happened.  Everything was working the week before and then while i was working, Teams went off line and I've never been able to make it work on that network since.

I've gone through all the settings between the two networks and can't see anything that's different that can't be because they're different models.  Only thing I haven't done is reset the BE10000 environment to factory default and start over from scratch.

Any ideas before I wipe and replace?