Can not download metadata XML and Attribute mapping is no longer optional, Version 8.0.0

[Panvite]

Installed Version 8.0.0 this morning and tried to add a SAML based Authentication for my AuthPoint 2FA.

Steps to reproduce

1. Click Use built-in SAML based Authentication
2. Add a Provider
3. Add valid Identity Provider Data
4. Save and try to download Metadata XML

Expected behaviour

Download of the Metadata XML should happen

Actual behaviour

If i do not fill out both displayname and email adress in the optional map attributes, it doesnt let me save.
On top of that, if i do fill them out so i can save and try to download the metadata xml, Nextcloud just jumps to my Dashboard, doing nothing.

Also: It tells me all the time that the metadata is valid even if i type nonsense in any of the fields.

It worked with 7.4.1 just fine on a different instance from the same hoster.

Server configuration

Hosted by Hetzner as Storage Share.

Nextcloud version: 32.0.6

Browser

Browser name: Firefox/Chrome

Browser version: both newest

Operating system: Windows