Where are these files located exactly? If you move a few of them to another folder you know for sure is being included in Search then do they show up in WIndows Search?
Next try these repairs to fix Search not working in Windows 11:
https://www.webnots.com/how-to-fix-windows-11-s...
https://allthings.how/7-ways-to-fix-windows-11-...
https://helpdeskgeek.com/windows-11/windows-11-...
https://thegeekpage.com/windows-11-search-not-w...
https://www.lifewire.com/fix-search-not-working...
https://www.maketecheasier.com/windows-11-searc...
https://www.youtube.com/watch?v=3HEJj4oyjlQ
Establish a Clean Boot to see if that resolves it:
https://www.makeuseof.com/clean-boot-windows-11/
Run System File Checker/DISM in WIndows 11:
https://www.elevenforum.com/t/use-system-file-c...
If that doesn't fix it then you can do a Windows 11 Repair Upgrade which reinstalls Windows while saving your files and apps in place, brings it up to the latest version by the most stable method, takes about an hour and resolves most problems: https://www.elevenforum.com/t/repair-install-wi...
Feel free to ask back any questions. Please report back results for all steps given so I know what else to suggest if necessary.
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