Soft pedal after hard turns

Disks rely on the flex of the axle / spindle to move the piston away from the disk a few thou.

Perhaps you have too much play in the spindles etc and the piston is getting pushed too far.

Also the optimum angle is 45 deg for the caliper.

Horizontal doesn't see much flexing, vertical sees too much.

This info was in a race suspension book from the 80s I had