Startup Security Utility Admin Permission I have a company mac with admn privileges. There are also other hidden admin accounts installed. Wanted to boot windows from external disk to play some Indi coop games 

To boot from external Disk I need to allow it in Startup Security Utility in Secure Boot with cmd + R

I can select my Admin user to authenticate. However my password is not accepted. There is no error message at all. 

For example If go to terminal and type 'resetpassword' I can authenticate with this user and would be able to change others users passwords.

Is there some specific authorization policy for Startup Security Utility which needs to be granted ? Or is something broken for this user ?
You have a Mac with a T2 chip, which requires an Administrator account with both a signed certificate and a SecureToken linked to that account, and the account that tries to change any of those settings in Recovery has to have the same matching SecureToken, a copy of which is held by the BridgeOS running the T2 chip.

Your IT folk have (quite rightly) locked that kind of thing away good &amp; proper. Sorry, but no coop today :)