Duplicate and Confusing Calendar Entries from Microsoft Bookings with Teams on Shared Booking Pages

I’m still waiting for feedback on my previous posts regarding duplicate calendar entries from Microsoft Bookings with Teams integration on shared booking pages.

I have now found out the following:
The second calendar entry titled "IT-Support" (italic, red, "No response required") appears only if the customer actually joins the Teams meeting. If I, as the employee, join the meeting first but the customer does not join, this duplicate calendar entry does not appear.

So the duplicate entry depends on the customer joining the meeting, not just the employee.

Does anyone know what causes this behavior? Could it be related to how Bookings or Teams handle meeting join events or calendar updates triggered by the customer’s presence? Is this a known issue or a configuration problem?