player cannot leave swimming animation without entering air block

When I am swimming and I press the sprint key, in 1.13 pre3 (what I expect) I leave the swimming animation as soon as I let go of W, in pre5 I don't leave the animation or technical state, if I look up, I still go up, unlike the normal swim in which I look up and it does nothing. (I am NOT holding ctrl or W in the picture)