Nice one! Thanks so much - issue with the Set Fields node has been resolved.
Edit:
Apologies, @mohamed3nan. Upon further testing, it appears there is still another issue - now with the Switch node.
The output from the Set Variables path is being passed through the “Get Open Slots” path of the Switch node. However, not for the Book Appointment path.
Sure. Also, I edited my earlier response (a follow-up question basically). Is it okay to continue discussing that on this thread? Or do I need to make a new one?