Created attachment 149445 [details]
A GIF recording of the tail sample problem

SUMMARY
Some of the stroke-oriented brushes' very first sample seem to ignore the stroke's direction and always match the same default direction, making them harder to work with.

OBSERVATIONS
After fiddling with the brush settings for a while, this seems to occur with the MyPaint engine brushes in particular.
Also, any parameter influenced by the Direction suffers from this issue, not just the Elliptical Dab Angle.

STEPS TO REPRODUCE
1. Create a new empty document.
2. Select the "i) Wet Knife Plus (mypaint)" brush, from Krita 5's stock brushes.
3. Make a stroke in non-horizontal directions.

OBSERVED RESULT
The brush's orientation is sampled across the stroke properly except for the very first sampled instance, which seems to have always the same default orientation no matter what.

EXPECTED RESULT
Ideally this non-oriented tail sample should follow the stroke's direction.

SOFTWARE/OS VERSIONS
Windows: Windows 10