So recently, repurposed some old sonoff tasmota devices - with new names, (changed everything but the IP remained the same) … even though I renamed/deleted entities via the tasmota add-in and on the entities themselves, my old dead sonoff devices (that I deleted via UI) would re-appear in the system again and then also the repurposed sonoff devices would come back with it’s old name.
Took a long time (a month) to figure out how to fix it. The only solution was to use MQTT broker and then delete the subscribed topics that way so that HA would forget about it. That is a seriously hacky/dev way to fix. Would appreciate if this could be managed inside the UI itself.