Hard to tell. I don’t use +roam flag, so I may confuse this further.
Where exactly do you enable Org-roam?
I think your error is caused by the load sequence of Org-roam and ORB. Both need to be loaded at the time when you get the error. Judging from your description, you have only Org-roam loaded.
My humble suggestion is remove +roam for now.
And then you either follow Org-roam’s documentation, and put something like this:
(use-package org-roam
:ensure t
:hook
(after-init . org-roam-mode))
Or equivalently (I think), you put:
(add-hook 'after-init-hook 'org-roam-mode)