Dovetail routing jigs are notorious for blowing out the corner of the tail board at the end of the cut when routing half-blind dovetails, because that corner is not backed up by the pin board.
Here’s my simple solution: Use your band saw to make a scoring cut before you rout the dovetails. Set its fence so the length of the scoring cut is slightly less than the length of the dovetails being routed, and set the stop so the width of the scoring cut is slightly less than the width of the dovetails being routed.
Make scoring cuts on all the corners of your tail boards (drawer sides). Now rout your dovetails and there will be no blowout!
– Bruce Kieffer