Hi. I have a Subtank mini v2 and have been vaping with it's rba head for a while. Now i don't have my rebuilding kit with me, but i have an occ coil. It seems to look like the one that was already screwed in when i got the subtank. But as i primed it today at morning and tried to screw it in, it would simply would not hold in place. Did my friend bought me a wrong coil ? I thought at first place that all subtank coils fit every type of subtank. Can i somehow fit it in or am i doing something wrong in the first place ?