In linked staves, the return to a nominal measure duration, if it corresponds to two beats (half-rest) leads to corruption

Version 3.6.2 / Windows 10

Steps:

1. New score for an instrument with linked staves, eg template Guitar + Tablature, default 4/4 time signature
2. Create a pick-up measure (or irregular measure within the score), with a 2/4 actual measure duration, in Measure properties
3. Save
   You are here: test duration 4.4.mscz
4. Now, return in Measure properties, and set again the 4/4 time signature as Actual duration
5. Save/Reload

Result: corruption (expected: 4/4, found 6/4)
Here : test save-reload 4.4.mscz

For fixing, create a full measure rest (Ctrl + Shift + Del)

• Depending my understanding, and the few tests done, this only happens if the creation of a second half-rest should happen (at step #4) and it doesn't - or, in a wrong way.
  For example, if we do 3/4 (pick-up measure), then 4/4 (step #4), it happens normally, because the last quarter rest is created (images below ) before saving.
  
  

But not with a 2/4 then 4/4

The change seems fine :

But not, after save-reload:

• Files with 3/4 change:
  test duration 3.4.mscz
  and test save reload 3.4.mscz