Navbar behavior bs5

Hi, good evening everyone.

That’s actually two questions, but I think they are well related.

I have a bootstrap 5 navbar. In small devices, when it’s collapsed, once I select an item, it remains open. I know it should load collapsed on reload, but I’m buliding a SPA page, and the navbar is part of the main layout.
Also, when it opens, does not overlap the background but drag the content downwards.
How could I change these behaviors?

Thanks!