Issue while using Resource Module to avoid double bookings

Dolibarr 19.0.1, with Hostinger

Good morning

I am using Dolibarr ERP/CRM for vehicle reservation management.
I’m encountering a small problem.

I’m using Resource Module for car Reservation.

In order to avoid multiple booking for same car, I create one resource for each car.

Then I create event (for Agenda) and add the resource

The issue is that when I validate the event, my resource is not added directly

I have to add once again manually this resource to see this added on my event

The problem is that when I create a second event with same date for booking (even if I add my resource), the event is created directly (no pop up) and I have to add once again manually the resource to see the pop up "resource already used).

Could you please advice me how to avoid this double adding of the resource?

Hope that you can understand my explaination.

Thanks a lot for your advice.

Best regards