I'm noticing a problem with my WB. where the fletching strikes the whiskers on the lower leftside the whiskers are being bent & some have broken off. This doesn't appear on the nock vane or the lower right vane. Doesn't seem to affect arrow flight. Local Pro shop was stumped, center shot & nock checked out OK. this is the 2'nd biscuit in a year, I changed the first for the same reason. Iv'e seen biscuits that are several seasons old with no wear, any ideas what could be causing this. BTW the bow is a PSE Stingray 26" 55#,shooting Browning Boss arrows.