Hi Chris ,
This is an inherent problem with braided line , one can't feel if the line has been nicked and over a week ago I just had a breakage some 5m from the PE to mono leader knot upon a strike from a medium sized GT , the line I was using then was PE5 Varivas Avani GT ( rated 70 lbs. ) which is considered the best in the market .
In order to avoid such , I reverse the line after a few days' hard fishing , the old line at the bottom of the spool and the new line on top thus getting twice the usage from one spool .
Jon .