@Tony I'm calling a victory. My network is now back up as it was before (save for any DHCP reservations which I'll do later). I've got the AP and all the guest networks running, all devices...

@Tony This morning, I swapped out the C7 and replaced it with the other new-in-the-box A7 I had. I just did the basic setup -- giving the WiFi my SSIDs and passwords, and just taking defaults on...

@Tony My next step was to swap out the C7 with the A7 today and try testing with it. So, great suggestion. (The C7 was purchased four years old (not old, certainly) but the A7 was purchased just last...

@Tony Well, I just checked after completing the prior post and it has happened again. :-( I checked before starting that post and all was well. So, I again disabled the guest WiFi on the router. :-(...

@Tony Thanks for the reply. This morning, I rolled back the C7 router to the previous version (3.15.2 build 170525). This is what I was running successfully before the upgrade. The good news is that,...

My home network is an TP-Link Archer C7 [v2, 3.15.3 build 180114 rel .39265n] as my main router. I also have an TP-Link Archer A7 [v5, 1.0.14 build 20200220 rel .33197(5553)] configured as an AP and...