Word always resets font to Calibri after closing and reopening document

Hi there.

We use custom fonts and they work almost all the time. Except when using them in tables. I can apply the font in the table just fine but when I open the document the next time the font in the table is resetted to Calibri.

I am aware that there are standard settings for the document that may overwrite my manually edited font settings. However I actually set the custom font in the "Modify Style" settings as can be seen in the image. For the table text this setting has no effect, though. Again, I can manually apply the correct font to the table text using the Font option in the Home tab. When upon reopening the document the font is resetted to Calibri.

Creating a new Style also does not work.

I really appreciate any help. I really invested so many hours in finding a solution but so far it was in vain. Unfortunately, I cannot send an example because of business secret reasons.

Kind regards

Note: I replaced the name of the font with "Custom font" for business reasons