Although slides that contain videos play fine on my MacBook, they won't when it is connected to a TV or projector via HDMI cord. It has worked fine in the past but doesn't now.
MacBook Air, macOS 15.1
I was using a slightly out of date MacOS and discovered today that the problem was more than just in Keynote.
No videos were playing properly with Keynote, QuickTime Player or VLC when my MacBook Air was connected to an external monitor via an HDMI cable.
After updating to 15.3.2 all is well!
videos won't play when Mac is connected to projector
