URGENT - Default Owner on records (pre-populated)

I need to make the Owner field populated by default with the user who is creating the record (same as the user who is signed in).

Usually if I make the Owner field required at the field setup level it usually does it automatically, however for Service Request object it does not auto-populate even after doing so.

As a workaround, I made the field NOT required.

Defaulted the Owner Id with UserValue('<UserId>')

Upon saving it populates the Owner field.

This is not ideal though.

Am I missing something or is SR different?

How can I default the Owner field?