Bee stands at the water level (which is good, but would be better if it didn't touch water at all) while following a flower only if you dive slowly. But if you jump into water and the bee has to rush to you, it will dive in 1 block and not come up (and consequently suffocate) provided you don't move.

The 160088 bug was a bit similar and was marked as resolved, but bees loving water has clearly not been fixed