Oliver,

Cable faults like that can be so easy to miss until you're right on top of them, and even then they can feel like the last thing you'd suspect...especially when everything else checks out mechanically. The fact it was repeatable at the same screw position is what threw me, I was thinking the ballnut!

Glad to hear it’s running sweet again though and I bet all that fresh grease didn’t hurt either

Nice to get a win on one of these annoying gremlins for once, thanks for confirming, it’s these little nuggets that really help others down the line when they hit the same sort of brick wall.