Komet,
I'd like you to try these two things, one at a time.
First -Â Change your Video Format in VIP Services in Settings to MKV (MKVToolNix)Â. Run at 1080p or 720p and see if you still have the sync problem.
Second - Do a clean installation of the latest StreamFab release, meaning use a professional Uninstaller such as Revo, Ashampoo, and many others (Google Uninstallers for additional free and pay programs) to uninstall SF. In addition, be sure to remove your current SF Log and Temp folders. Then download the latest StreamFab release from the Sticky announcement at the top of this forum and install it fresh.