Do you have a roster with available spots, but your potential customers are being waitlisted because the class is 'full'?
What may be happening is that your roster has an uneven amount of available spots for class dates, while on full camp/semester or monthly pricing, without a drop-in pricing setup. When a schedule is set up for full camp/semester pricing, the schedule will only allow a customer to register if they're able to book a spot for each class of the entire semester or camp. Otherwise, single drop-in spots won't be buyable.
For example, in the schedule below, three students booked the entire semester, which means they have one spot reserved in each class.
However, one of the students cancels their booking for the first class, which leaves one open drop-in spot I can fill.
However, because I only set my scheduled activity up for full semester pricing, without any drop-in option/pricing, customers don't have the ability to register for that one drop-in spot.
To fix this, I just have to go to Schedules> click the time frame> Edit activity> Pricing> toggle on Drop-in pricing> Save & Continue. From there, a customer can register for the drop-in spot without me having to manually add them from the backend.