Road bike falls our of tacx blue motion mounts

Can anyone explain to a newbie why my bike falls out of the trainer? The adjustable screw with the blue locking nut is secure, the axel is inserted coreectly, and the handle is housed properly. Even so, the damn thing jumps out and I fall off sideways, which is a bit embarrassing on a static bike. TIA

Can you post a picture of the setup?