Steps to replicate the issue (include links if applicable):

• with the skin Vector 2022, the sidebar (main menu) is actually hidden by default
• go p.e. here, open it manually by clicking on the burger menu, and change article by clicking on a blue link (p.e. this: "Syndicat intercommunal à vocation multiple")

What happens?:

• the sidebar collapse again when you change page

What should have happened instead?:

• when you unroll it voluntarily, the sidebar should remain visible until you hide it by yourself (and vice versa).

Software version (skip for WMF-hosted wikis like Wikipedia):

Other information (browser name/version, screenshots, etc.):
messages on fr.wiki here and here
I can reproduce it when I'm logged-out, not when I'm logged-in (Windows 10 Home, Firefox).