Magma cubes will jump after landing too quickly and even instantly if hit while in midair. On the other hand, in Java there is quite a lot of time to wait around and if hitting them in midair you still have enough time to back up.
A video demonstrating the issue: https://www.youtube.com/watch?v=WQ-wvmRbHjs
(Left = correct behavior,Java; right = too fast, Win10)