Still can't change search engine on chrome - what am i missing?

Does it say 'managed by your organization' anywhere in the menu? Then it's a policy, not an extension. Type chrome://policy into the address bar and you'll see what's being forced. On a work laptop that's IT and you leave it. On a home PC nobody should be setting policies, which usually means some junk software installed one, and you'll want to clear it out.

If it keeps flipping back after you set it, that's an extension rather than a setting. Chrome will usually say so - when something else is controlling search you'll see a notice on that setting instead of a free choice. Disable your extensions, set it, then switch them back on one at a time until it breaks again. Nine times out of ten it's something that rode in with an unrelated download.