Shared folder with edit right not working as expected

Nextcloud version (13.0.2):
Operating system and version (eg, Ubuntu 16.04.3 LTS):
Apache or nginx version (eg, Apache 2.4.18):
PHP version (eg, 7.1):

The issue you are facing:
We have several smaller sharing issues, this is one of the most annoying. Some users simply unable to edit files (mainly XLSX) in a folder which is widely shared with edit privileges. Nor via the web interface and by using the desktop client to download it. In this case Excel opens the file in Read-only mode…

Anyone had similar issues? Any idea how to resolve?

Is this the first time you’ve seen this error? (Y/N): N

Steps to replicate it:

  1. Create a user group
  2. Assign users
  3. Create a folder and share with the group with edit privileges
  4. Upload an XLSX file
  5. SOME of the users CAN edit the file, some can’t