I've got a 6 second video timeline animation. 3 layers with 2 tweens (simple enlarges), total. When I render video at H.264 (or any codec) I get to the 'Exporting Video' dialog box, where the progress bar doesn't move and the cursor spins. Meanwhile, Photoshop immediately writes a a 6 second .mp4 to disk, but the file contains no animation. Sometimes, I can hear the fans on the computer fire up as if it's doing some heavy processing.
I've given Photoshop and Media Encoder full disk access and restarted. Still no luck.
I'm also experiencing the same issue. Like others, most functions of PS CC 22.3.0 are incredibly slow, but especially the video export. I'm rendering an even simpler 2 layer, 2 frame file that takes 15 minutes to export when this used to take seconds.