Program was started registered, logged in.
In the queue I had 5 videos. Started in the evening. The next day the last 3 videos had watermarks. This has happened to me 2x now. Very annoying!
My guess: The program checks the registration not only during startup but also while the program is running. Such a behavior is new to me. My PC is mostly offline, so probably the unsuccessful registry check during the program in the middle of the night.