Mine will fall from the glass if they are not submerged in water. Under normal operation in the water I have no issues with mine falling.
My glass is 3/4"
it creeps down counter clockwise, if I hang the wire straight over the edge of the tank it doesn’t move with the wire supporting it. If I run the wire from the side out the back of the tank it immediately sags before my eyes.
water or not the pump shouldn’t move. MP40’s and MP60’s have zero issues
Either way they are going back, I won’t own a product from a poor company that fails to admit it has a problem and wants to sell you on a pi** poor add on sale