Masks needs to be recalculated one by one after opening the catalog, in version 11.4

Background:
Photographers outsource their editing in LR classic to me. They provide me with a catalog and smart previews, but not the raw files. I install the catalog and smart previews on my mac and edit the photos. When editing, I also use the new mask feature / select subject / invert / to make edits to the background only.

Steps to reproduce the problem:

With a photographer I just started working for I have the following problem: When she opens the catalog with my edits, she needs to recalculate each mask, photo by photo. The mask itself shows an exclamation mark, when she clicks on that it says: subject 1 needs to be recomputed (see screenshot). If she does not do that, the masks with edits are not applied when exporting to jpg. This happened in 4 different catalogs.

Versions:

I work on a Mac with Catalina version 10.15.7 and LR 11.4 

She works on a PC with Windows 10 and LR 11.4

Expected result:

Masks with edits should work directly after opening the catalog. This problem does not occur with another photographer I work for. But this photographer also works on a Mac.