Iam not sure if the new patch fixed some of that bug, but ever since I switched my keys for steam from the default Shift +Tab to some other key, it happens less, since the blue skill key is set by default to the Shift key hope it helps
I still use shift+tab for steam, but I don't use shift for any of my MNC skills. I've only had the blue skill bug once or twice, a very long time ago. My blue skill is on Mouse4 (thumb button).
I'm the same, don't use it shift for anything and have it bound to mouse 4, but get the bug all the time. Some games I even have it on my first spawn after choosing class....guessing there's more to it than keybinding :/
