The conventional wisdom in ham circles is that thicker elements result in broader bandwidth. That goes along nicely with structural stiffness, and thus most VHF

The conventional wisdom in ham circles is that thicker elements result in broader bandwidth. That goes along nicely with structural stiffness, and thus most VHF Yagi-Uda antennae are made with their elements cut from tube instead of rod, for example. I'm not sure which changes you made exactly, but I wouldn't be surprised if the end effect was thickening the relevant portions.