Hi, when you say - you obviously don't mean immediately after a fresh installation, but after you've installed some programs and configured some things.
Some suggestions:
1. Try the start menu troubleshooter
Start Menu Troubleshooter in Windows 10
2. Do you have any system restore points - have you enabled system restore? - you can use, and do any of them take you back to a point before this problem occurred?
3. Do you have any disk images you can use to restore your PC to an earlier state? (We strongly and repeatedly recommend using disk imaging.. can often save so much time, avoid seeking technical help, and even save you if your disk fails completely or is badly infected etc etc).
4. Failing the above, how does it look if you create a new user for test purposes?
5. Failing the above, progressively undo changes you have made.
6. An in-place upgrade repair install
may fix it unless your user profile is damaged (see (4) ).
If no resolution,
1. Clean install,
2. Create a disk image (e.g. Macrium Reflect (free) + its boot medium + external storage for images).
3. Make a small number of changes as you have previously, check your start menu is ok.
If so, update your disk image.
4. Repeat (3) until the start menu no longer works. Restore your PC from your latest image and don't do whatever broke the start menu again.