Har diskuterats här tidigare men nu har Trådfri-Utvecklarna på reddit identifierat bugg med att gateway tappar bort enheter och planerar en fix inom en snar framtid.
View: https://www.reddit.com/r/tradfri/comments/nm25ao/devices_dropping_outbecoming_unavailable_in_the/
Devices dropping out/becoming unavailable in the Home smart App
We have been looking into this and identified a bug causing dropouts when a gateway is restarted/losing power. Bulbs/devices become eventually unavailable in the app but can still be steered through remotes. A fix will be released as soon as possible. Lost devices can be brought back by simply cutting off power, e.g. unscrewing a bulb/using manual light switch, un- and re-plugging a power outlet. The TRÅDFRI driver might need a few seconds more to be cut off entirely from power. /IKEA Home smart