Hello. I have noticed that on occasion, I tend to lose skill points that I used on the menu (compass). I do not know how, why, or when this occurs, but it has led to me being unable to use my main crossbow (Slate Bow) due to not having Lvl.10 defense skill, whilst having used the bow just this morning without any issue. I could not find any other bug reports about this (or I didn't search well). Neither did I find any explanation on whether or not this is a thing that happens for a reason.