Parts not loaded from uncompressed folder

Hallo,
I am saving my projects into uncompressed format because using Git repo for my work.
In MuseScore 3 it was one mscx file, now in MuseScore 4 it is full unzipped folder.
Yesterday I notice this probably bug in MS4 version 4.4.4 on Windows 10:

• have created main score with number of instruments - staffs
• when I create parts from main score and save project, parts are saved to subfolder.
• but when I reopen project (by clicking on mscx file in parent folder) the parts are not loaded at all.
• when open some part from "parts" menu, the part is created again and replace files in subfolder.

May be I am doing something wrong, but I can't find way how to open uncompressed folder with parts together. I there any way?

thanks
Vladimir

PS: if project is saved to compressed mscz file, parts works correctly.