It is still broken for me and I give up. I do not want Start10 anymore nor will I continue to suggest it to people who want a more traditional, less cluttered start menu. It is ridiculous that I pay for a product that the only support I can receive is someone on on a forum posting links to a how to that have already been looked at. This is an issue with how Start10 handles being installed before the latest Windows 10 update. If you roll back the update, uninstall Start10, update Windows again, then reinstall Start10 it works. If you roll back Windows 10, reinstall Start10, then do NOT update Windows 10 ever again it works. I do not have the time to backup my PC and roll back Windows 10 in hopes that my start menu is usable again. I can still find Microsoft Store apps with Start10. I can still find Windows pre-installed app with Start10. I cannot find ANY application I have installed on my PC and I know with 100% certainty that Cortana is installed, my 4 hard drives have been reindexed, and that there is nothing preventing me from finding applications I install using the default Windows 10 start menu.
This whole situation is just stupid and I'm done with it. Good luck to anyone else who finds themselves with this issue. I'm just glad that the only thing I use Windows 10 for is games and streaming. I don't have to deal with the pile of trash when it comes time to do real work.
I am sorry you are experiencing issues, but you do unfortunately appear to be alone in this continuing. Something in the OS update clearly did not go well which unfortunately is a risk with how Microsoft push OS updates to everyone these days as a small percentage will go badly.
If you ran the purge file then nothing remaining from Start10 should have remained, so a new install will be identical to how things would be if you had only just discovered Start10.
If you are not getting search results then something in the OS is stopping Start10 getting them.
I don't know if you have enabled any settings in the OS which stop Start10 even getting access to search as there are some additional privacy options which could break things in theory.