Done, and upgraded to latest version hoping for a solution.
The new MP4 files are generated with a different codec. Google Photo show black screen, VLC player/Mi Video/Nova player Can reproduce the file.
But the latest version introduce another bug in continuous recording. In case of Watchdog event on a camera, alla cameras stop to record and timeline stays empty. Restarting the pc (or simple the software) the timeline becomes full but recorded video is still interrupted to Watchdog event.
Also rebuild the DB does not solve the graphical issue.
Bi is not configured as service (NEVER done)
Blue iris DVR with flac compression, encoder h264 with default settings