What mount are you using? Are you well balanced and within the mount's weight capacity? We believe the problem with the Star Adventurer was that it was overloaded and mistracking, causing the guider to autocorrect, probably making the situation worse. We have yet to try and confirm this with a lighter load.

Me? AZ-GTi. Yep, I'm very well balanced. Bearings are all cleaned, polished, and greased. Cables are managed such that there are no snags (almost learned that the hard way once). It's not a periodic or regular occurrence for me either, just every now and then guiding seems to get very lost (and not because of clouds) for a couple of minutes, and then suddenly settles down.

Here's the rest of my guiding from last night.

What kind of load is on your rig? Are you at the halfway point, or at, or surpassing, the load limit? My friend was over capacity on the Star Adventurer. We think think that's the problem. Also, did you polar align using Ekos?

4kg, not over limit. Polar aligned with ekos. It seems quite unlikely to me that it's a mechanical issue, given that it's not continuously bad or jerky tracking, nor is it only at a specific pointing angle. In fact, most nights I don't see this at all.