Short answer
HubSpot's KB: ad blockers commonly break the ads tool. You must be an admin on the Facebook ad account. Accounts with billing issues or policy violations show as Inactive. Removing the HubSpot integration in Facebook disconnects it from every HubSpot account.
1. In HubSpot
The relevant screen in my demo portal.
2. Worth knowing
Log in to Facebook as the right user before reconnecting.
3. Related
Connecting Facebook ads and disconnecting.