Task bar icons context menus won't open unless explorer.exe is run with admin rights

I have a Windows 10 computer which recently began to fail to open right-click context menus on taskbar items. The search box also has odd behavior, it blacks out until you enter something in it and then backspace over your entry, then it displays properly. Both these problems go away if explorer.exe is run with admin rights. Clearly some item in the path of these functions has bad access restrictions, any good ideas as to how to locate the problem?

Found a way to diagnose this issue. Through a Google search, found instructions to open diagnostic summary data in Windows: Settings > Privacy > Diagnostics & feedback. Scroll down to "View Diagnostic Data", turn the setting on, then click on Open Diagnostic Viewer. This will take you to the Windows store, download the app and install.

Clicked on the "Problem Reports" left hand menu pick, scrolled down and found many entries for Search Application, all like this:

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Search application

Description Faulting Application Path: C:\Windows\SystemApps\Microsoft.Windows.Search_cw5n1h2txyewy\SearchApp.exe Creation Time: 12/8/2021 2:17:28 PM Problem: Stopped working Status: Report sent

Problem signature Problem Event Name: MoAppCrash Package Full Name: Microsoft.Windows.Search_1.14.2.19041_neutral_neutral_cw5n1h2txyewy Application Name: praid:CortanaUI Application Version: 10.0.19041.1320 Application Timestamp: bdfaf044 Fault Module Name: combase.dll Fault Module Version: 10.0.19041.1348 Fault Module Timestamp: baf10630 Exception Code: 80070543 Exception Offset: 00000000000862a6

Extra information about the problem Bucket ID: b8245a700e899c43668c574363557344 (1624769512514876228)

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That exception code is in winerror.h, translates to "Cannot open an anonymous level security token".

Searched on that, found this little gem: http://ctimls.com/Support/KB/Error%20Fixes/Fix_Login_errors.htm

"Cannot Open an Anonymous Level Security Token

To fix a "Cannot open an anonymous level security token" browser error:

Open the Windows Control Panel
select Administrative Tools
double-click on to open Component Services (in the List)
double-click on (or click the + beside) Component Svcs (in the white box)
double-click Computers
right-click My Computer
select Properties
select Default Properties tab
change the Default Authentication Level to "Connect"
change the Impersonation level to "Identify"
click the OK button. "

My setting had Authentication Level as "None". Changed to "Connect", problem solved.