Big Sur Beta 7 breaks SMB?

After the upgrade from Beta 6 to Beta 7 I am not able to connect to any smb-shares any more. I tried it with a Windows Server, Synology DriveStation and a Debian implementation. I’m directly getting the message Error with connection.

still waiting for any response and support. thanks!

https://jiofilocalhtml.co.in/
https://router-network.uno/