P: Problems with rotation/crop

LR 6.3 resets crop after rotation.
Step 1 - rotate picture via slider
Step 2 - crop picture
Step 3 - rotate cropped picture (via slider) -> crop removed!
I use this function very often. In LR5.7 everything works as expected, in LR 6.* never.

Here is what works:
- Step 1 - crop
Step 2 - rotate cropped picture (via slider)-> crop stays!
But:
Step 3 - crop refinement
Step 4 - rotate refined crop -> crop reset to former state!
- Also using the crop frame corner to rotate arbitrary does functioning correctly.

Often when you make crop refinements (off center) you have to adjust the rotation angle because of the different perspective due to off center cropping. Why Adobe ignores this bug so persistently. I prefer to use the slider for rotations instead of direct rotate using crop frame corners.