If I understand this correctly, the Modal property when enabled is intended to disable mouse lock in first person. I’ve used this property in GUIs to do this exact thing.
However, at some point, the property disappeared entirely and mouse lock was no longer being disabled.
The property has since returned, but it does not do anything.
Video:
Expected behavior
When the Modal property in a visible TextButton or ImageButton is enabled, the camera should not be locked to the mouse cursor when in first person.