Index / Codebase lost / not being used / can't be found

Weird hiccup today, wondering if anyone else has encountered this one.

I spent the morning using Composer, which was well familiar with the index and the codebase. Was working great.

I took a break, quit the app, and came back a few hours later only to find that the AI, which ever model I chose, could no longer reference my codebase.
It had no idea what we were working on, was confused at the context, and can’t provide any help, code or even thinking.
I’ve deleted the index, computed again, watched the index fill up with my files, but the AI still can’t find it.

I’ve wasted a number of hours trying to figure this out, anyone had this issue before?