Problem spotted on win32, may also affect Linux (TBC).
The code runs and it looks like we're downloading the frames from video memory, but when scrolling detection runs it finds that the picture has not changed and so we end up not generating any screen updates.
Forcing scrolling detection off does not help: the video encoders also find the picture unchanged. This also applies to the NVENC encoder when using the picture data found in the CUDA buffer which would indicate that the API is just not capturing new data. (rather than a download / usage problem on our side) This could be a driver bug, or a problem with the API uncovered by newer drivers.
r18299: CUDA buffer mode no longer enabled by default
Linux was not affected.
this ticket has been moved to: https://github.com/Xpra-org/xpra/issues/1763