Hi all, I might have the same issue.  I tried restoring purchases as described and it keeps saying it cannot connect to iTunes at this time???  Yet my phone connects to iTunes store just fine.

Ok, when it asks you to log into your Apple account, just hit cancel.  It should then skip that step and just synchronize with Eventide's server.

Alternatively, you could deregister your H9 Core, close and reopen the app, and reregister your Core.  That will in end effect do the same thing, and resync your Core with Eventide's server.