I've got a 2020 Magnitude SV34 and I've had the bed apart to access my water pump and electronics. I have a King Tilt-a-View and it only has the raising and lowering mechanism in the center of the bed.
If only one side is moving I would take the mattress off and look for obstructions on the side not moving or look at the metal frame to see if something has come apart at one of the hinge points.
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