@dc42:

Which firmware version were you using when that happened?

First noticed on 1.10, but also seen on 1.17-based firmware. But it was a lot less frequent on 1.17.

I have found that having pressure advance enabled results in layer offsets (likely caused by skipped steps) about once in 50-100 hours of printing. It seems more prevalent on parts with lots of small segments and complex geometry.

Since it's so infrequent it's pretty hard to debug, so I've turned it back off. Which is a shame because it does help sharpen corners up some with long bowden drives.