Same here, quite busy with 2.1 but yes I think I will need to create a case.
There was also a issue defining what role is actually required, even after adding the correct contact group and adding “Modify existing hosts” to the automation user I was not able to register. I had to revert back to cmkadmin to get it to work.
it was also not clear if you could use an automation user as the TLS registration command expected a password and you “only” have a secret. Compared to the agent update registration you have to use the -P or -S options while supplying password or secret. More confusion 