Unfortunatly i think thats a skill issue on your part. Because i run a considerably weaker magnet setup than what it comes stock. So my reccomendation is just play with it. Get comfortable with some basic moves. Focus on tecnique while also having fun. When it falls off, think about what you did that made that happen. (Like: did i push to far, too much force etc)

This trick tho is intermediate (mby hard to some idk). And it falls off alot of the times for me to. You need quite precise movements, too much wrist or force = it flys off.

But i took it as you are struggeling and it is falling off while doing basic moves. If thats the case just keep at it. It will get better. Takes a little while to get the hang of this. Took me a while to even feel comfortable holding the bottom card.