Additional features, settings, or issues not covered by specific Microsoft Teams categories
Hello Alina_G,
Files in Teams group are stored in SharePoint, to edit team member access to the file, it is suggested to edit file access permission via SharePoint:
- In Teams, select one team group and the channel, and click files tab.
- In files tab, click Open in SharePoint.
- Select the file you want to edit and change access permission->click “…”->Details
- In right pane, click “Manage access”
- Set Team members access to “Can view”, and add specific users you’d like to grant access via “Grant Access”.
Here’s test on my side:
You may try above method to see if it meet your needs.
Besides, when you said “I must set member to Owners for them to be able to use Files tab”, in general, all Team member can see the files tab, to better know your situation, could you please share a screenshot of issue symptom with us for checking?
Best Regards,
Anna