Canyon CF8 cockpit issue

[Sudo]

Hello,

Whenever I’m in my aero position, my left handlebar turns from left to right. I’ve traced the problem back to the stacked spacers underneath. I’ve torqued the bolts to 4nM (as specified) but that doesn’t help.
The right sides doesn’t move and I don’t see what’s different between them.
Anyone ever encountered the same issue?

Edit: would carbon paste between the spacers help?

[MI-XC]

@Sudo

Edit: would carbon paste between the spacers help?

I’d try carbon paste and torque to 4.5-5nm. Also check that the spacers don’t have an imperfection that’s preventing it from sitting flush.