GCal Syncing for Appointments+

One of our customers had enabled the "Add Google Calendar Button", but experienced issues with the times not syncing correctly, so she disabled it. She recently mentioned that she was considering re-enabling it, so I did some testing and found issues with it.

The first thing I did was book an appointment with the "Access Google Calendar and submit appointment" option checked off (see raintreeappointmentsyncing1). It opened my Google Calendar in a new tab, but the appointment did not show up even close to correctly (see raintreeappointmentsyncing2), so I discarded the event and closed the tab. She has a "My Appointments" shortcode on the page above the calendar, which adds a Google Calendar button when the "Add Google Calendar Button" option is enabled (see raintreeappointmentsyncing3). I clicked that button and it again opened my Google Calendar in a new tab, but this time it showed correctly (see raintreeappointmentsyncing4).

My question is why isn't the "Access Google Calendar and submit appointment" in the Appointment Confirmation syncing correctly when the Google Calendar button provided by the "My Appointments" shortcode is?

Note: all of the testing was done on the customer's staging site http://raintree-hubbli-com.jono39.staging.wpengine.com/raintree-parent-teacher-conferences/