Slideshow keeps freezing when using a projector

I have a 2017 MacBook Pro running OS 12.0.1 (this machine is the one with the two Thunderbolt ports) and I have a projector with an HDMI port; I just bought a brand new USB-C to HDMI cable and hooked it up. I have the photos saved in a folder and when I click on "Start Slideshow," one or two slides will show and then the process stops. One other thing to know is that my Slideshow has a few short 1-minute-long videos in it; not sure if slideshow supports videos.

I tried my using my iPhone 11 Pro Max with a Lightning to HDMI cable adaptor and it was working perfectly for a few minutes, and then it too began to freeze. Now it will only show a couple of slides before it too stops.

The projector also has a USB port, an SD card slot, an IR port, and a VGA port. I would love it if I didn't have to buy yet another cable if at all possible.