Likely an issue with start menu search. I had it a year or two ago, when I first installed Win 10, start menu search couldn't find anything. I can't remember details since it was a while ago, but I just searched the web to find the culprit.
Now since I have fixed the issue, I can search any application installed and get it in moments. Try and see if maybe you also have an issue with search itself.
Now since I have fixed the issue, I can search any application installed and get it in moments. Try and see if maybe you also have an issue with search itself.