yet another JB fitting inquiry

My new JB fits much better than my first device which was way too big. However I find with the Jb I grow out of tthe back end when I get an erection as opposed to my old device I would grow into the empty space in the front of the device. Its almost as if the back half of my penis gets hard and the whole device including the base ring slides forward down the length of shaft until there is nowhere left for my cock and balls to move. Is this normal? Im pretty sure the base ring fit is correct.

Exact same thing happens here... I'm not sure if I prefer him growing into the device or the growing base thing.

LRC mentions she enjoys the bulge that appears between her body and my base ring, noting it serves as a sign of her arousal.