Cannot access samba mount after upgrade from 28.0.1 to 28.0.3

I am getting

External mount error

There was an error with this external storage. Do you want to review this mount point config in the settings page?

when I try to browse my samba external storage in the Files app. In the settings page, it seems to work, validating it takes about a second before the green check mark appears which I assume means nextcloud is testing credentials. Also, I can access the sambda server with smbclient, and the password wasn’t changed.

What could I be doing wrong here?

I use this external mount with the nextcloud backup app for off site backups, so this is a bit worrisome.