No tag functionality availbale

Nextcloud version 17.0.1 (this problem was observed under 16.x, too)
PHP Version: 7.3.10

The issue you are facing
I have the same problem as this user here had last year:

Unfortunately, there was no answer so I am trying again:

I am not able to add tags to files - there simply is nothing available regarding tags. I can’t search by tags, and in the file detail window there is no way to add tags.

Is this the first time you’ve seen this error? : Yes

Steps to replicate it:

  1. Open a file to “Details” view in Browser
  2. No option to enter tags
  3. No filter option on the left side

Any ideas? This one drives me mad. Without tags, we also can’t use stuff like “File retention” and files access control based on tags.