I'm having an audio and video out of sync issue that I don't have with version 2.79. I have created a new video project with Blender 3.0 VSE, in the composer I bring as input a video of 1920 * 1080 and 29.97 fps. This is a Sony camera file in MXF format (422 10-bit). I use the compositor to crop my subject from the green screen and I export the text to the MOV QT Animation format with the Alpha channel (19201080 29,97fps)*.
In a new project, I import my MOV file that I got with Blender. On a second track, I import the original video (MXF) to use the audio track. These two videos are with the same number of frames per second and are perfectly aligned. However, when one of the two video strips is turned on or off with the H key we notice on the monitor that the frames of the two videos are not synchronized and when I export the rendering, the sound is completely out of sync. I don't understand what's going on. With version 2.79 I don't have this problem.