Dynamics and hairpins
OS: Windows 10 (10.0), Arch.: x86_64, MuseScore version (64-bit): 188.8.131.5252, revision: 2c21b2a
Open the attached score and take the reset. The dynamic in M9 is unable to assume the default vertical position, and cannot be nudged upward: ticking "Allow diagonal" on the hairpin releases the dynamic. (Another solution is to move the hairpin 0.5 sp to the right, but, still, when you tick "Allow diagonal" there is further upward movement of the dynamic).
Tick "Allow diagonal" on the same hairpin, select the front handle and nudge it upwards: the front end moves up a short way, then the back end moves downwards instead.