I sink during swimming

When I swim I sank when I don't lift up with the right buttons (lift up/down) the same time.

That makes no sense: In reality I sink under the water when I don't move, but when I move I stay at the surface.

Why was that changed? That already worked as described.

Can you please change that back to a realistic behaviour?

My current problem is that I need one hand for swimming forward, one to stay at the surface and one to control the direction. That is one hand too much.