Hello,
This problem I and others have encountered is described at
https://answers.microsoft.com/en-us/windows/forum/windows_10-win_cortana/windows-10-creators-update-windows-key-s-search/2e25a9dc-6ca5-4341-8e88-b4a3d26cb7edI went throught the standard (free) tweaking program but it didn't resolve it.
The solution I found at this above link site has worked and please consider for inclusion at tweaking. :
"
Confirm your search is working at all: Create a new user and check if search works. If it does, go on (with your old user where search does not work).
Backup RegKey: Computer\HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Search
Delete the whole Key (including all sub keys + values)
Access the search (e.g. press windows key and try enter something)
Nothing will happen. Try this a few times, when it starts working again the key has been recreated.
Either import the backup or just use the new settings (which you may want to adjust)
Regards, Paul