Dteck - Clear Magnetic Case for Apple iPhone 17 Pro Max with 360 Rotating Kickstand Slim Shockproof PC TPU Hybrid Cover - Black

What are the dimensions?

There was some excess flash on the clear piece that I trimmed, but phone still moves in case. Is the black foam on the left side responsible?

Is the case supposed to be immobile once secured on the phone? My phone (17 Pro Max) is loose in it and the left side can slide forward, backward a little bit in the case. It seems like there's a little flash on the left edge of the clear plastic back

Is the grip ring strong enough to attach a lanyard or crossbody strap?