It renders, composites and saves the image just fine, but refuses to move to the next frame. GUI remains responsive.
It's a large scene (alembic animations, 7 million tris with hair on top of the meshes) and for some reason reducing the size of the scene solves the issue. I'm sure I'm not running out of RAM though, as I have 16Gb and Blender is using only 3Gb to render. Plus, like I said, it renders just fine it's just not moving to the next frame. CPU usage is at 100% when it gets stuck. I'm using the latest version.
Switching from Optix to CUDA seems to help, but it also gets stuck after 5 or 6 frames. It also takes 6 times longer so I'd rather not use that.
Specs: Ryzen 5 3600
250Gb SSD (100Gb free)
[EDIT] Sadly I can't upload the .blend file as this project is for a client