Thank you for your answer, it helped me find the source of this problem.
In the hidden folder called ".idea" that you mentioned, there is a "workspace.xml" file, which contains the metadata settings for the Digi facets. This file is included in the ".gitignore" file.
This means that if a Digi Project is uploaded to a GitHub repository, then the "workspace.xml" will be excluded. This is what caused my initial problem. Therefore, removing this line from the ".gitignore" file fixed the issue.
For anyone else who experiences this problem, perhaps consider this solution too.