For several weeks Alexa was happily linking with my 8 Tapo T100 plugs.  Then one morning a week or so ago they were all apparently unresponsive.

I have tried everything I can find: re enable the skill, reset each plug, factory reset Alexa, re-register Alexa, remove Tapo & Alexa apps, buy WiFi extenders so the plugs only suffer less than 30db loss.  Still Alexa does not find a plug although Tapo continues to work fine.

What else can I try or should I simply accept that linking to Alexa is too flaky to be viable?