Remote Desktop connection to Azure AD Joined computer

I'm doing some testing on a standalone (no on-prem AD sync) Azure AD test tenancy, and have set up a user (non-admin) account, installed a base Windows 10 system, and joined it to Azure AD (shows Azure AD Joined) using the user account. It appears to have created that account as a local admin, so I've enabled Remote Desktop and am attempting to log into it using the test user from my normal work computer (local AD joined, Hybrid Azure AD in production tenancy).

That will not work, source and destination need to be in the same tenant.

For more info: https://docs.microsoft.com/en-us/windows/client-management/connect-to-remote-aadj-pc#set-up