Thank you Tope! I actually have an iLok 2 and an iLok 3. I put the Vanilla copy on 2 and Ultimate on 3.
When my partner plugs the iLok 2 into his MacBookPro, he can boot PT Vanilla 2019.5. But to get to Cloud Collaboration, I had to sign him in with my account. Then we downloaded our test session to his MBP, but it closed the session on my MacPro running Ultimate saying it was in use on another machine.
Can he create a separate Cloud Collaboration login some how so we can collaborate simultaneously on a project?