@smithhn I will go on record to confirm that a main ASUS router reset seemed to be a one-step cure-all. If all fairness, my router has had some suspicious WiFi behaviors in its past, the 2.4G is a fairly heavily-loaded spectrum in this home and in recent hours around the failures I had been playing with MAC address exclusion filterings for smartphones as well.

Curiously, both of my "other-branded" WiFi indoor color bulbs did not exhibit the problem, I performed only a restart function on both Kasa HS220 dimmer switches with no joy, but taking a cue from this thread I tried a cold-restart of my router (which incidentally caused it to "scan all channels" by default), and that was indeed my TP-Link solution as well.

Still not certain of exactly the original cause of the issue, nor why the TP Link products seem to "feel" the most "susceptible", but they recovered nicely for me and have given me no other trouble since. For the record, they are several weeks old at this point, and have been subjected to merciless Domoticz and Node-RED JavaScript bashing, and have proven robust in that regard.

Everything worked fine with Kasa before but after the Network Name (SSID) was changed Kasa devices aren't available.  Clueless of what to do next.  Should I change it back to see if it works again?  Resetting the channels didn't work.  Thanks.