using powerpoint with zoom

I've been doing online presentation via powerpoint for the last 3 years. Following the last zoom update and Office updates when I play a video that is part of the powerpoint the screen freezes and flickers, sound is delayed. when the video finishes after 5/6 seconds normal service is resumed. I'm using a MacBook Air. VenturaOS, Zoom and Office are all up to date.  Colleagues using Macs and the same presentations are having no problems. Any help out there ?