Maybe a stupid question. Resides domain 1 and domain2 on the same server or is domain2 pointing to a different server.
In the first case, domain2 also has IP address 1.1.1.1 and you have to place a redirect on the server; in case 2, you have to do the redirect outside of the MiaB
It’s quite uncommon, nowadays, to put multiple ip addresses on a server, for hosting.