Thanks. In my case it’s procedural and generates in many different directions, depending on random seed.
The solution from the post that You have mentioned didn’t helped, but something very similar did: Instead of taking spline direction + rotating, I took spline Up Vector (‘Get Up Vector at Time’) and set it as Set Spline Up Dir when adding spline mesh component.
This fixed the twisting, but created a problem when spline is going up or down :
It’s like the roll is off, but I’ve tried to set roll manually to the spline roll at the time (or at 0), but nothing changed. It’s strange that is happens only if spline is going up or down…
Update: Another screenshot showing the problem:
