Settings sidebar missing

I’ve got a new site that is missing the settings sidebar. When I go to site settings it pulls up the General settings page, but the sidebar with General, site access, publishing, etc simply isn’t there. it’s only this one site in my workspace that’s having the issue. Is this just a random bug, because it was working a few days ago, or is there something I may have accidentally turned off?

I am having the same issue! Does anyone have an answer? * am attempting to transfer domains between sites and can’t get to the settings to do so.