Good chance it's a hard hit and like Gary says you don't have a tray. You are mounting each end of the servo independently to the fuselage so that the servo housing is bearing the brunt of the impact flex in the fuselage rather than a servo tray. Also it looks like you have mounted the receiver to the fuse with Velcro without a thin piece of foam in there. That could have made a hard life for the receiver. I normally use two layers of Velcro with a thin sheet of foam between them.

Denis