Can you please tell me which browser/os are you using? I'll look into it, although it works my laptop/phone.
P.S. Unfortunately I had some bad experiences with leaving contact info public.
Brave browser (basically Chrome) on Windows 10, and same behavior on Safari on iOS.
I'm not sure what is happening. I can replicate that behavior only when I disable javascript. If that case you can't close it as it relies on the url hash.
edit: typo
I don't have JavaScript disabled on any device. As an aside, it is possible to implement your feature without JavaScript (with <details> and <summary>).