The course visibility settings are not correct. Visibility is set at the course level and applied to the course itself and all sessions contained within. This can be updated from Courses > click on the desired course > Edit this course > set to Public to be visible to all, Followers to be visible only to customers who have clicked Follow on your Gymcatch page or Private to grant access to a specific list of customers.

If you course is set to private visibility, you or your customers may not be on the Access list. Navigate to the course or session Details screen > click Access to view the current list of permitted customers and make any changes.

The course visibility and bookings preferences are incorrect. For the course and its sessions to be open for booking (subject to the session drop-in settings) this needs to be set to Booking and listing on the course Details page. For the course to be closed for booking but session open for drop-ins this should be set as Listing only. If it is set to Not visible then neither the course nor its sessions will be visible.
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