Troubleshooting

Keyboard shortcuts do not work

Ensure Focusable="True" on ZoomBorder.
Ensure the control actually has focus when keys are pressed.
Verify EnableKeyboardNavigation is enabled.

Pointer dragging does not pan

Check EnablePan.
Verify PanButton matches the button you are pressing.
If the child handles pointer input aggressively, confirm events still bubble to the ZoomBorder.

Wheel input behaves unexpectedly inside a `ScrollViewer`

Review WheelBehavior, WheelWithCtrl, and WheelWithShift.
If the control lives inside a ScrollViewer, also review ScrollViewer and Logical Scroll.

Gesture tests do not fire pinch or scroll handlers

Register gesture handlers before window.Show().
Prefer MultiTouchTestHelperFactory or GestureSimulator when you need recognizer-aware tests.

Grid or zoom indicator properties are set, but nothing is rendered

These properties configure state only.
Rendering of custom grids and zoom indicators must be supplied by the host application.

Saved or serialized state is not restoring the exact expected result

Check whether bounds or resize behavior is adjusting the imported matrix.
Confirm the target content size matches the original state context.