py4web: 1.20231115.1
Created one user in auth_user (Id = 1)
Enabled Tags, verified that auth_user_tag_groups exists, open table within the administrative dashboard _dashboard, select create a record.
Both Tagpath and Record Id fields are available for edit, however, the Record Id field is implemented as a lookup (drop-down), and no records are available for selecting.
If I programatically call groups.add(1, 'manager'), it then adds the appropriate record, just not on the UI.
Testing with SQLite DB, on Pop!_OS (Ubuntu) Linux,
Cheers