Filament will not retract unless power cycled

When the AMS refuses to pullback the filament during a print or an unload, I have successfully managed to make it work perfectly fine by just power cycling the X1 Carbon. I don’t quite understand what is happening that is different when it starts up compared to the unload but this has solved the issue for me at least 5 times in the past couple of days.

Did you open a support ticket already ?

Yes I did and I believe they added the fix in a patch.