All locations showing booked slots when appointment is made

Hi there,

I'm having trouble figuring this issue out, and good old Google didn't help much.

When booking an appointment with Appointments+ at one of our 3 registered services (all bound to their own locations), all services on the front-end show that slot as booked. In other words, when we book (for example) something for February 4th at noon at Service A, Services B and C ALSO show that slot as booked.

I've tried deactivating all plugins, reverting to the twentyseventeen theme, and have torn through the plugin settings, to no avail.

We're also using Membership 2, and this page is in our members-only area, so I've enabled Support Access for you guys. Here's the front-end page that allows users to book appointments in one of our 3 services:

Thanks for your help!

Cheers,
Nick