Behaviour problem on mobile only (accordion + popin)

Hello everyone,
I am having a behavior problem on mobile concerning an accordion and a pop-in modal.

1: The accordion at the bottom of the page works very well on desktop, but on mobile, it does not close when clicking on it, and I don’t understand why.

2: The modal that appears by clicking on “join waitlist” also works well on desktop, but on mobile, when we close it (via the “close” button), the design of the whole page is modified and the margins on the sides disappear.

I tried to find the problems but well, I admit that I am without solution right now. If anyone can help me I would be very grateful! :slightly_smiling_face:

Here is my site Read-Only:

Thank you
Have a good day !

Here is the published website :