I've only managed to recreate the issue 3 out of 20 times. I was standing next to the wall and messed up a parry and got hit with a fireball. I was then knocked back into the wall.
I haven't been able to recreate it myself, however I have been rearranging the collission code, so hopefully that solved it. The fix will be live with the next update which should be soonish seeing as there's some smaller things I need to change/fix as of now.