Here is what appears to have fixed it for me:
Restarted in Recovery Mode and ran Disk First Aid on all volumes: all were OK.
• Followed these Apple Instructions:
• Choose Apple menu > System Settings.
• Open Spotlight settings:
• macOS Sequoia or later: Click Spotlight in the sidebar, then scroll down and click the Search Privacy button on the right.
• Drag the disk or folder that you want to index again to the list of locations that Spotlight is prevented from searching. Or click the add button (+) and select the disk or folder to add
• From the same list of locations, select the disk or folder that you just added. Then click the remove button (–) to remove it from the list so that it can be reindexed.
• Click Done, then quit System Settings. Spotlight will reindex the contents of the disk or folder. This can take some time, depending on the amount of information being indexed.
Waited a minute, invoked Spotlight, searched for several apps in my Apps folder and it failed to find Apps and put them right at the top of the Spotlight hits about 80% of the time nor did Spotlight displayed the word “Indexing” under the results which is usually does when you try and re-index a drive.
So ran Terminal and did this:
Last login: Sun Nov 24 12:31:21 on console
bobby@Roberts-iMac ~ % mdutil -sa
/:
Indexing enabled.
/System/Volumes/Data:
Indexing disabled.
/System/Volumes/Preboot:
Indexing enabled.
/Volumes/TimeMachine 1:
Indexing enabled.
/Volumes/TimeMachine 2:
Indexing enabled.
bobby@Roberts-iMac ~ % sudo mdutil -i on /System/Volumes/Data
Password:
/System/Volumes/Data:
Indexing enabled.
bobby@Roberts-iMac ~ %