instead of pick all instances id use for each coin and then compare two variables distance(coin.x,coin.y,character.x,character.y)<500 Set coin magnet true
that should do the trick.
also are you sure that coin on top is a normal coin? and not a UI coin? make sure all coins have the Boolean Magnet on them.
it might bee also because your movement condition is triggering for each coin but then u block it on trigger once.
here is an example coin-magnet with the code above in it. and i removed all the behavior dependencies you have in the code there is simpler on my capx less complicated.
I updated the file added the powerup magnet on player pick also so its easier to understand how to apply to your case! :) if you have problems with your post "waiting for moderator" just edit it and re-post it again.