Steps to reproduce bug
1. Create a new score in 4/4 time
2. Right click on an empty part of the first measure and choose "Measure Properties..."
3. Change "Actual Duration" to 1/4
4. Press "OK" to dismiss the dialog
5. Right click on an empty part of the first measure and choose "Measure Properties..."

Expected behavior: Nominal duration should display 4/4 and Actual duration should display 1/4 as set in step 3

Actual behavior: Nominal duration has become 1/4 and Actual duration has become 4/4.

MuseScore version: 3293 self built on trunk

(Operating System: Windows 7)