After one of the recent updates, I found that if I add a new MQTT entity and specify a unique ID, it does not get acknowledged by HA. If I edit the yaml and delete the unique ID, it shows up. If I go back and restore the unique ID it disappears again. This is true for binary sensors and sensors (I haven’t tried others). I also find that if I edit an existing (actively recognized by HA) MQTT entity, that has a unique ID, it disappears when I trigger a reload. To bring it back, I have to delete the unique ID which was working previously.
I searched the releases for breaking changes that relate to this and found none. This seems like a defect to me. Does anyone else see this behavior?