Adorner Thumb DragDelta changes values incorrect when Adorned Element is rotated

_This issue has been moved from [a ticket on Developer Community](https://developercommunity.visualstudio.com/t/Adorner-Thumb-DragDelta-changes-values-i/1413029)._

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[severity:I'm unable to use this version]
I have created a test application (attached) that can be used to demonstrated the problem and test the solution.
The DragDelta horizontal and vertical change values of the Thumb are incorrect when the Adorned Element is rotated with a positive angle or a negative angle more than 90 degrees.
When rotated for example at 60 degrees, the horizontal and vertical change values appear to increase in an exponential rate causing he adorned element to rapidly disappear off the screen/canvas.
When the adorned element is not rotated, the DragDelta change values are like:
dX: -0.3 dY: -1.0
dX: -0.3 dY: -2.0
dX: 1.5 dY: -0.4
dX: 0.9 dY: -0.9
dX: 1.4 dY: -3.2
dX: 2.3 dY: -2.2
dX: 3.0 dY: -2.2
dX: 1.8 dY: -2.7
However, if the adorned element is rotated > 0 degrees clockwise, or more than 90 degrees counter clockwise, the DragDelta change values are like:
dX: 2.3 dY: -13.1
dX: 38.7 dY: -333.8
dX: 353.0 dY: -209.5
dX: 467.2 dY: 185.6
dX: 169.9 dY: 589.6
dX: -442.6 dY: 601.3
dX: -907.6 dY: 17.5
dX: -687.7 dY: -863.2
dX: 325.4 dY: -1,304.8
dX: 1,505.3 dY: -651.8
dX: 1,746.2 dY: 971.2
As a result the adorned element rapidly disappears off the screen.
In this case an adorner to use for dragging is Not Useable.

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### Original Comments

#### Feedback Bot on 5/5/2021, 08:14 PM:

We have directed your feedback to the appropriate engineering team for further evaluation. The team will review the feedback and notify you about the next steps.

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### Original Solutions
(no solutions)