Hello! Posting this in case someone else has the same issue I did - hopefully save them some frustration :)
Symptom: Working in a project with video. During playback, the video in the Video View works as expected. During recording, the timings get off, by either a little or a lot (or the video barely seems to work at all). Generally, I would see recording about 4 seconds ahead of/faster than where it should be by 20 seconds into the video.
Cause: There's something (at least on my combination of hardware) that throws off the video speed during recording if you use an Audio count-in on the metronome. It seems to be related to the duration of the count-in - one measure at a fairly high BPM will cause a little skew. 3 measures at a slower BPM will make the video pretty much unplayable.
Workaround: Either eliminate the count-in, or switch the metronome to MIDI. MIDI doesn't seem to exhibit the issue. The issue comes up even if there are no audio tracks.
Version: I had the problem on Sonar Platinum 21.10.00 Build 32, Kingston, 64-bit.