I met him once but it wasn't a friendly interaction, he never appeared again after that, it never said anything about being an orc either so I'm just a bit lost at this point, Zorro has no option to buy potions yet either, just the usual five options he usually has. The only people who appear in the gym now are Trald and Gen, and I can barely interact with them
Have you already received the PATS app? I remember there being a part where you needed to meet 5 or so people before the game continued, but I think that's before what you mentioned.
Other thing that comes to mind is seeing the events in the park at night with Trald, but not sure if those are required for the story to continue.
Edit: Also, you should have a text from Zorro in your messages asking you to meet him (Zorro Shop Talk), not sure if you need to read it before talking with him to allow you to access the other options.
Sorry, can't think of anything else. You might want to raise a bug ticket, since that quest should have ended as soon as you met Bloodthirster at the gym after taking the potion: https://blackcatstudiosdev.atlassian.net/servicedesk/customer/portal/1