Frustration!

I think I'm missing something- possibly quite obvious- here and I need your help if you can!You know how I've been battling with half rectangle triangles? Well I reattempted them again, prepared to trim them down and make them bigger from the start. This is how my first Wallander block (of 100 I might add) turned out...The Flying Geese side is longer slightly so the points don't match, which I don't mind so much because I could say they were "meant to look like that", however I'm pretty sure quilt show judges won't think the same. Fine I thought, I will paper piece them instead. Here is my foundation, nothing unusual here...BUT the same thing just happened, EVEN THOUGH I was sewing on the lines! HOW is that even possible?Any thoughts? I may have to simplify it even more  and make all 4 quadrants a HRT, but that's not really what I wanted. Why is this so difficult? PS competition on my previous post is still open for a couple more days so don't miss it if you want to be in the drawing for last month's  spare copy of Popular Patchwork Magazine. And yes it is open internationally ;)