Windows search stopping working after brief period

Hello,

tried to search for this, but found no working solution.

On my PC with Windows 10 Home (22H2) windows search ceased working  - it worked months after installation. Now it is working only for a very brief period (not exactly measured but estimated seconds, max up to one minute), then it ceases working.

When I press Win key on the keyboard and type a few letters, I can quickly launch my applications (for example Thunderbird or Notepad++) via shortcuts in the start menu and other indexed search locations. But only for a brief time, as mentioned above.

I did some tests and investigations and found out that restarting the service "Windows Search" helps, again only for the same brief period.
In services.msc service Windows Search is listed as "running".
When I run the troubleshooter (manually or from Settings -> Search -> Searching Windows -> Run the indexer troubleshooter...), it gives "Windows Search is not working" as a result of checks.
In event viewer, I found no events related to Search (except when I restarted the service, then there were six events, two from the "Search" source and four from the "ESENT" source -service stopping, then four related to db, then service start).

 I tried to "reset" Search by setting in registry SetupCompletedSuccessfully=0 in Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows Search, but it did not changed anything.

Any hints on what to do are welcome, thanks.