Troubleshooting Classes in WordPress:
Edit the Class in WordPress.
Copy the Event Instance >> Ticketing URL and save it in a text file for reference.
Delete the Event Instance >> Ticketing URL and Save the WordPress event.
If the PatronManager event is properly configured, the event instance ticketing URL will reappear after saving (because it is synced).
However, if the ticketing URL does not reappear, that indicates that the event is not properly set up in PatronManager. If not properly configured, the event will not appear in the checkout form. You can paste your saved URL into the event temporarily, however customers will not be able to checkout.
If you've changed the start time or schedule of the class in PatronManager, you'll want to also fully delete the event instance with the old time in WordPress, and try resaving again.
Common issues to troubleshoot in PatronManager:
Is the Ticketable event set to Event Custom Type >> Class?
Does the Class have available allocations?
Is the Event Instance date (the start time of the first class session) set correctly?
Are the onsale and offsale dates set correctly?