Search does not work on a table, while on others does work

I’m using the WPDA Premium version.
I have a table of music scores with about record a thousand records and a related table of the author of about 250 records.
I usually manage the record in my tables via the admin interface. Cause the number of records I use the search to find the records I have to work on. This works fine until few days ago.
Now I’m experiencing problem only with the music score table, search on the authors is working fine as usually, while on scores table does not. And even more, the search on scores obtain a list of about 200 records (with little differences on different search) apparently with no relation on what was searched.
I’m not conscious to have modified anything about the table description.
Anyone have any suggestions?
Thanks

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