Why does it authorize in Bitrix in the admin panel, but not in the frontend on the site?

Question

1C-Bitrix

And if, on the contrary, you first log in to the frontend, then you will automatically log in to the admin

panel. Something incomprehensible happened to the sessions after reloading nginx in VMBitrix and now this is nonsense. I don't know how to get everything back to normal. The code of system or components was not picked in any way.