IDEA can't find scala files or symbols

Even after indexing finishes, IDEA CE fails to find many symbols (it appears all scala symbols fail to be found). The oddest thing is that it also can't find plain scala file paths that usually works even while class indexing is still going.

I have tried the usual things of "Invalidate caches and restart", as well as up and downgrading IDEA (2020.2, 2020.1.4, 2019.3.5) and stating over with a fresh clone of my repository.

Failing to find a class that is open in the editor:

Failing to find the very file that is open in the editor:

(Note how it does find a compiled class file with that name in jar file, but not the actual source file that is open in the editor.)

In the little funnel of the search dialog I've got everything selected, including scala and scala-worksheets.

Aside from the search dialog, Scala integration is working fine. When I open a scala file (clicking through the project tree like a chump) everything highlights fine and even go-to-definition and find-usages all work fine. The only thing affected it seems is the search dialog.