FTP Value

I recently started having problems entering the FTP. Previously I was always able to do this via the devices or via Garmin Connect. Recently I had another totally pointless automatic FTP calculation (although I have switched off Automatic) and I can no longer get rid of it from GC. The correct FTP is entered for each device (watch and Edge). GC shows me the wrong, self-calculated one. Does anyone have any idea how I can fix this? Or similar experiences?