Striders are randomely floating above lava and blocks sometimes

I was using the striders in the latest version, and I noticed that my strider was moving unusually slowly. At first I thought that the lava was only one block deep, and the strider was on the block, not the lava. I checked under the strider and saw that the lava was about 10 blocks deep. I then saw that the strider was actually floating above the lava.