I played for quite some time now and I am convinced there is a point where Specter Knight will ignore the jump key while running on the ground.

I haven't pinned it down precisely. My impression is that you can't jump for a few frames while turn around mid full speed horizontal run.

Does anybody else notice this? Is it a feature and you aren't supposed to jump while turning horizontally? Or is the game just ignoring my keypress due to a bug?