Hello J B,
Greetings... Thank you for posting this in the Microsoft Q&A Community.
From my understanding, you are not able to see any role on the subscription other than the Owner role.
This might be a result of glitch. Try signing out, and authenticating again. Also, try with another browser or try doing this from the Incognito tab. You can also try this by using another user account with an Owner role on the same subscription within the company.
Also, if there is any other subscription within the tenant, see if you can assign a role on that.
If the issue persists, raise a ticket to Microsoft Support from your portal.
Let me know if this helps.
Babafemi