Infernal Blow/Glacial Hammer & Resolute Technique

I'm currently playing an Infernal Blow Duelist and also have some Glacial Hammer experience. In both cases I picked the Resolute Technique keyston. And to my surprise, I'm not always hitting. My 1st thought was I desync, so I always hit /oos when it occurs. And guess what, I'm exactly where I was supposed to be. So, unless crabs, spiders and bowman skellies suddenly developed some awesome block skills, I'm pretty sure there's something wrong here.