I did not change any of the visual settings after applying the noted fix. Still Dark / Light / Custom Color / Custom Theme. I think there are several issues working here:
- Maybe changing the visual settings, maybe before, maybe after applying update 1909 could break search. I don't know if re-changing them could re-break search. I tend to try lots of preferences, find one I like, then stick with it.
- Search can be 're-initialized' / force re-up of index settings, thereby re-enabling proper indexing, by revisiting the search settings (per re-post of instructions above, this thread page 30 & page 3). Then wait for indexing to catch up.
- Changes to large amounts of data in non-indexed files and/or file types, lots of file moves, software installs, backups, or other heavy use of large or data intensive files, plus maybe high system / processor use, puts strain on the background search process to keep up. Then click to search does not respond quickly / correctly / at all as a result, appearing broken. App shutdown and restart forces re-indexing, fixing search.
- Search function changed in behavior. Now improved in some ways, frustrating in others.
I have not poked around in the Search Settings, or elsewhere, to see if there are options for changing the priority or behavior of the search process.
I agree with another poster earlier in this thread - report this in the other Microsoft Developer Quality forum (have to go look up the name).