The elements are not displayed in the frame when I click on "select"

Hello to all,

I have a problem when I do "select" to get the elements in the frame. When I click on the elements I want, nothing is displayed in the frame and I can't press "done selecting" to validate my choice. I'm on a Mac, maybe that's why? I tried on several sites and nothing changes.
Thanks for your help.

@max_asse Hello, could you, please, provide us with the targeted website?