While I had a light in Home assistant with similar behaviour, and no info at all in the logs, I decided to remove it from HA, and add it as new device, with also a slightly different name. Problem “solved” 
Maybe you can do the same with the Fibaro.
Your flows will break though; When you have many flows involved, you can use this neat script to auto-repair the flows:
I always use the “replace device name” version, which has not failed me once.
It’s important to save the ‘old’ device name up front, and name the ‘new’ device slightly different (you can always rename it to the ‘old’ name afterwards).
