Bridge change the rating stars

Hello, my problem is this: I wanted to extract from my archive the images classified with more than 3 stars. I created a library and then set a filter not to include all folders in the archive. I then set up an export. The problem is that Bridge changed the number of rating stars in the selected images to 5 stars. Do I have to reclassify the entire archive? A big nuisance. Did I do something wrong? Can I recover? Thank you