Punching Strider of the top of lava stream will make it stay on current Y axis

I was building a Central Strider Point(CSP) in Minecraft: Java Edition v20w13b, a lava stream coming from the roof was flowing on to it, hence hiding it. But that is not the point, I noticed that the Striders were fly up to the planks on top hiding the CSP. So, I tried to punch one near the edge off, but when I did it stayed and didn't float back down when I punched it again, the same behavior. I have attached a screenshot so you can see what I mean.