I've dealt with this mess more times than I care to count. Once Meta removes the hacker but the Business Portfolio remains inaccessible, it's almost always because the asset got slapped with a security or integrity hold. The recovery path essentially comes down to proving ownership of the business and demonstrating a historical connection to those assets.
right now, the most critical thing is whether you still have access to any connected elements tied to the Business Manager, like the original Facebook profile, a verified domain, the ad account billing methods, business documentation, or the Page itself. Those are the pieces Meta leans on to validate ownership during escalation. The frustrating part is that their support is wildly inconsistent unless you manage to hit the right internal recovery flow.
One thing that would help clarify your situation: can you still see the Business Portfolio inside business.facebook.com at all, or has it completely vanished from your account?
