The problem I’m seeing is with the External Storage Name field on the Personal External Storage configuration page.
All External Storages on that page have the same name; ‘Seagate-Public’ in my case.
These storages do have correct names on the file browser pages and I can change the names properly on the configuration page. But when I return to the configuration page, they once again all have the same ‘default’ name.
The problem started with an update from 12.0.3 to 12.0.4
There are no errors reported.
FWIW: I found a resolution to this ‘problem’ this morning.
Nextcloud is actually working just fine. My password manager was actually filling in those fields with whatever data it thought should be there. I told the password manager to forget about the Nextcloud URL and everything came up as normal again.