Hi,
I'm trying to index a new (to me) bike, and having some problems. Got it indexed at the back then when I moved the front to the small cog I noticed the chain was 'skipping' on the rear jockey - it's not always aligning with the teeth and sometimes catches on a chain link edge.

I don't have a tool to check hanger alignment, but will look to acquire one, but wanted to check if it's likely to be that?

It's Shimano Ultegra

Here's a video