Appointments+ showing busy for all slots, unable to create new appointment

The calendar on my display page is set to a specific worker and was working fine.

I was fiddling with the code and found out how to hard-code a public list view for a specific provider.

Once I got this working, I added 3 service providers and their associated services. When I visited the booking page again, all slots appeared busy.

I replaced the modified shortcodes file with the stock one from the plugin. The problem persisted.

I then upgraded to 1.4.3 and still the problem persists.

Shouldn't the calendar have reverted to a working state if it is all stock code and no modifications remain?

I have granted support access, and was hoping someone could take a look and tell me why this is happening?

The calendar having the problem is here:

An odd note, the other calendar for a different worker is fine, here:

Thanks for your time,