Observe that the Homeless Services Coordinator role is defined as in a default installation (contact a type and contact b type are both 'individual')
Create a new "Housing Support" case with an Organization contact for the Client.
Open Manage Case page for this case
Under Roles accordion, click the pencil icon to edit the "Homeless Services Coordinator is (Case Manager)" role
Observe pop-up overlay "Reassign Homeless Services Coordinator" where you would select an individual for this role
At this point:
Expected behavior: This pop-up contains a contact reference field allowing me to type a contact name or email address
Actual behavior: This pop-up may be displayed partially outside of the viewport, with no way to scroll to see all of it; in any case, you can see -- if you're able to use Developer Tools to make the thing display within the viewport -- that the expected contact reference field is just a plain text field; also the Save and Cancel buttons are non-functional, and the only thing I can do is to click the X control to close the pop-up:
Workaround
Edit the Homeless Services Coordinator role to allow Organizations in the Contact A position.
Repease the repro steps above and observe expected behavior.
Other thoughts:
Testing on client sites indicates his is not limited to the "Homeless Services Coordinator" relationship type; instead, it's happening for any relationship type which is confiugured as the type for the Case Coordinator role.
Not sure about how best to design a fix from the UX perspective. Prevent case creation? Warn in System Status?