Setup Assistant continues requiring internet connection after unenrolling the Mac from MDM. How to fix it?

I bought a MacBook, which was enrolled in MDM. The owning organisation has unenrolled it from MDM, however, the macOS Setup Assistant still points out that the Mac is registered to an organisation and requires an internet connection. How can it be unregistered to enable macOS offline installation? I see that it is a new feature of Ventura to require an internet connection in the Setup Assistant but it should not apply to my Mac given it was legitimately unenrolled from MDM. Are there some additional procedures to take to release the Mac from the organisation completely? Attaching a screenshot with the unexpected internet connection requirement:

Internet Connection Required

The Mac is registered to an organisation and requires an internet connection to complete the setup. Join a Wi-Fi network or connect via Ethernet to continue.

MDM/DEP status:

$ sudo profiles show -type enrollment
Error Fetching Device Enrollment Configuration: Client is not DEP enabled.
$ profiles status -type enrollment
Enrolled via DEP: No
MDM enrollment: No