Audio echo on video playback and export after macOS 12.4 update

Hi there! We create videos with two different audio channels and, when both of us are speaking at once, we layer the clips on top of each other and have channel 1 or two enabled on each clip. It used to work great! But since the update to 12.4 it now randomly echos on playback and sometimes doesn't. It sometimes is also in the video after export, even if it didn't happen during editing playback. Any suggestions? It's pretty terrible!