Apple Watch passcode greyed out

Hi All,

since I paired my Apple Watch Ultra with my iPhone 13 (corporate managed) I had set it up with the Unlock with iPhone feature hence I have never set up a passcode. Although this is quite convenient but if I left my phone home by mistake I was and won't be able to unlock my watch in case it gets locked.

Is it possible to enable both passcode and Unlock with iPhone features?

Another thing is when I want to add a passcode I see I cannot change any settings on the Watch App on my iPhone in the Passcode menu (all is greyed out even the Unlock with iPhone enabled button) and the same is on the Apple Watch itself under Passcode menu (also here all greyed out).

Any ideas or advises?

Thanks in advance.