I've seen this many times, generally from underspined arrows. Most of the arrow charts are off on the weak side and will result in the arrow being too weak to absorg all the energy out of todays bows. 13 ft. for 25 grains is alot, should be more like 5-6 ft.
Basically what it's telling you is that the extra speed is making it calculate more KE. This however is misleading because of the loss in momentum, and the loss in downrange KE. Lighter arrows will hit with less momentum and lose more speed downrange.