Hi Micha, Bitdefender should not cause any problems, I think it compliments Windows Defender on my system. Some parts of Win Defender still remain active. The advantage: Bitdefender will watch his system and provide full cover and watch the system until he either decides to keep the AV or remove it. Bitdefender does not interfere with MSFS and should not degrade it’s performance. There is always a possibility that there may be another virus lurking in the background too. I hope this is just a false-positive.
Charles.