When you run a test a see the error "CRM access has been revoked from Lead Access Manager", it may be due to Lead Access being customised in Business Manager.
To make sure your account has access to leads for the page you're using:
Go to Business Settings from your Facebook ads account
Under Integrations, you'll find Lead Access. Click on it, then click on your page. Make sure your personal facebook account is listed here.
Now click on the CRMs and check to see if LeadSync Lead Ads Notifications is listed under apps. If it's not, click Assign CRM's and add it.
Updated on: 22 / 02 / 2021