MacOS – Finder doesn’t find duplicates with (1), (2), …, (n) in filename

You can use the find command to show you the target of the symlink then have awk throw away the rest of the line. Then wrap that in a loop that tells you what it's doing then feeds the names to mdimport:

for linktarget in $(find ${HOME} -type l -ls | awk -F'-> ' '{print $NF}'); do
    echo "importing ${linktarget}"
    mdimport "${linktarget}"; 
done

It's probably easier to cut and paste this little script since there are some spaces that are easy to miss. (like the one after the arrow in the awk statement).

I would suspect a corrupt file. It may be just damaged enough to stop Spotlight reading it properly.

If you select the file in the Finder and hit the space bar does it open in Quick Look? If it doesn't then it is broken.

Try opening it in Excel and copying and pasting everything into a new file.