I think it’s an improvement suggestion. So the idea is in the topic. I don’t remember where I got used to it, but it’s very convenient. Now the behaviour of an instance is closing a side panel only with pressing on navigation button. Next cloud instance is 23.0.4, runs on ubuntu 20.04. lts. Web-client Firefox 91.9.0esr
PS I just checked … It is already working as I suggest in core nextcloud functionality, such as files and options, but it’sworking only with pressing a navigation button in other apps, such as Deck, Notes, Talk, etc.
So the solution might be in development policies for apps, for developers to take this into account.