Aneros MGX fits snugly in me.

Hello! So I’ve recently started using toys. In initial couple of sessions the toy would cause involuntary contractions but now it seems to fit snugly in me. It doesn’t move much although with arousal i get hard and leak some precum. The lack of movement wouldn’t allow me to do contractions of my pc/sphincter it just feels uncomfortable.

I do relax alot so that isn’t the problem. Should I change positions? (I currently lie on my back with knees up) or should I change the lube? (I use a liquid based lube).

Please help me out!