Slow motion clip loses slow motion when uploaded to iCloud.
I shot a slow motion clip of my son's dog on the iPhone 13 Pro. I then exported it from Photos on my Mac mini without conversion. Using QuickTime Player I trimmed it and saved the trimmed clip. I placed the trimmed clip in my iCloud folder. When I play the clip on the Mac Mini it plays in slo mo, when I play it on my phone it plays at normal speed. The original clip on my iPhone is playing in slo mo.
Mac mini, macOS 12.0