"Unexpected error during account creation" when setting up Gmail (G Suite) in Mail app

Our compancy uses G Suite and since a few weeks we have NextCloud. I’ve installed the Mail app and now I’m trying to set a connection with G Suite. With imap host imap.gmail.com and port 993 (or 143, doesn’t matter) I keep running into the error “Unexpected error during account creation”
What I’ve tried so far:

Connect with an email address from another domain works perfectly. But we want the Google addresses :slight_smile: