i see "_1" filename postfix (before file extension) on this screenshot:
https://ibb.co/Y0SWCc7usually this happens when you add a file, which already exists in the library, and this new file becomes a duplicate. probably, later, you have deleted duplicated files from disk, but not from playlists.
now, about this screenshot:
https://ibb.co/2dbBVpjdo not try to delete duplicates, which physically don't exist. use "replace with reference to the kept file" option. BUT! be careful to mark as duplicate to be replaced the files, which don't exist, keeping the files, which exist. i don't know if this can be automated.
and replace database/playlists links to not existing duplicates by the links to existing files (using the same duplicate manager) for the case from 1st screenshot in this post (for files with filename ending with "_1").
if these files don't exist in the library, but only exist in playlists, then change mb settings to store playlists as .m3u files (prefs> library> playlists> library playlists> change MBP to M3U). .m3u is plain text format, which can be opened, e.g. in notepad++, or just in windows notepad). remove "_1" form filenames in playlists using notepad(++).
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NOTE FOR ANY FILE OPERATIONS ON THE TRACKS IN THE FUTURE:
do all file operations on tracks contained in the library/playlists only using MB (either use "tools> organize files" menu item or use "computer" node in the left navigator panel for manual file moving).