I have that issue too but with all possible strings/characters.
B14 ex pizza: B1 + X ray etc. Lol.
Or 114 airthrow: 11 god ray.
With hellfire 114 teleport: 11 flame aura.
That will happen if the input is too fast. Need to slow the special cancel a little bit down after inputting the string (or do everything a bit slower need to feel the timing). When i get the god ray i know that in the heat of the battle I do it too fast.
Sux and annoying (at least to me) but thats it now since last September (despite the fact that release check is OFF off course).