MP60 not staying in place no matter what

[14 foot reef]

One of my MP60 keeps dropping or sliding down the glass about a 1/4'-1/2" then stops, but that dropping makes for a vibrating and noisy pump.

Does anyone have a remedy for this. EcoTech had no suggestions as they said the magnet can't lose its pull or power, therefor it should not be sliding out of the placement.

Any help would be appreciated.

MP60 is mounted on a double 1/2" thick glass panel, so total 1" of glass. I have 2 of them, only one of them continues to slide out of place.

 

[WVNed]

One of mine did that. I got a new wetside and it stopped. That was on 1/2 inch glass.