Philipps Hue Light "not rechable", but works in Hue

Hello,

I have a light in my Philipps Hue Setup which is always shown “unreachable” (“nicht erreichbar” in German), but I can control it in my Hue setup well and it never has a problem. But Home Assistant will not control the light. The On/Off button is disabled. I guess it is because of the reported state “unreachable”. Is there a way to fix this and force the device to “reachable” for example?

best regards
Bumbum

I’ve not run into that situation before. But if I did I might try deleting the bulb from the Hue hub, and re-integrating the same bulb with Hue again.