Styles in the parts of a MS 3.5 file with parts imported in MS 3.6 are (unwillingly) reset and not saved after changing.

Steps to reproduce the issue:
1) Load a MS file with parts in it, made with MS 3.5 (for example the attached file Bach, J.S_Musikalisches Opfer, BWV 1079_Ricercar a 3_vi+va+vc_02PV.mscz ). Choose 'Keep old style' (but other options will give comparable issues).
2) Compare the result of the score and the parts with the versions seen in MS 3.5. The styles of the parts will be changed more than the styles of the score. (See also the attached pdf file, made with MS 3.5 Bach, J.S_Musikalisches Opfer, BWV 1079_Ricercar a 3_vi+va+vc_02PV-Partituur_en_partijen.pdf ). This is especially seen in the music font and text styles.
3) Change some styles in the parts (for example to reflect the styles in the score), especially in the music font and text styles.
4) Save the file and close it.
5) Open the saved file.
6) Check the parts for the changes in the styles you made. No changes are found. They appear not to be saved.
In this process, I used a newly saved style (mss) file for both the score as the parts, but that seemed to have no effect.

The overall status is that I cannot use or change any MS 3.5 file which already has parts in it (which in my case will have many format changes), or I have to rebuilt the parts all over again. In the update process from MS 3.5 to MS 3.6, I was not able to retain MS 3.5, so I'm stuck.

OS: Windows 10 (10.0), Arch.: x86_64, MuseScore version (64-bit): 3.6.0.487915773, revision: 1977cb3