Fedora 34, One of the involved algorithms has insufficient security level

Hi!
After an upgrade to Fedora 34, gnutls-cli gives me a
`*** Fatal error: One of the involved algorithms has insufficient
security level.` when connecting to my university mail server.

With `gnutls-cli --allow-broken`, connection works and I get this
result `- Description: (TLS1.2-X.509)-(ECDHE-SECP256R1)-(RSA-SHA1)-
(AES-128-CBC)-(SHA1)`.
Using `gnutls-cli -l` I can see that SHA1 in combination with tls1.2
seems to be forbidden.
Also, `gnutls-cli-debug` tells me it needs to disable TLS1.2 (why is
this?).
Might this be the reason for the error/is there a way to find out?
Is it a bug in gnutls or misconfiguration in the university mail
server?

Thanks a lot.
Best
Philip

P.S.: gnutls-cli 3.7.1