As its only 3 characters, its likely that causing you issues with finding, rather than the ampersand. mysql search, by default, has a minimum 4 letters for full text search. You would need to contact your hosting company if you wish to have this changed, as its a mysql setting.
This may help you if you are doing this yourself
https://dev.mysql.com/doc/refman/8.4/en/fulltext-fine-tuning.html