With the new slime block's properties of a decayed bounce, the Decay of the bounce height is less the smaller the jump is, therefore, a smaller jump will produce a larger bounce proportionally (if I am correct in my test)
Tested Examples:(100, 75, 50, 25 and 12.5 were tested, the other results are in the .txt file)
A 100 M. Jump will make a 31.625 M bounce. 31.625 Percent of the original
Whereas a 12.5 M. Jump will make a 7.5 M bounce. 60 percent of the original
If this were to be extrapolated out, in some instances the bounce would reach 100 percent, but at very small values. It has what the computer sees as and infinitesimal

Due to the way this works, it seems that with certain heights that you jump from, the height does not always decay to zero. this causes the Ground test to spit out True/False Repeatedly. I believe this is due to the Ground test detecting such small changes that the y coordinate test cannot detect. Therefore it shows change, without the y coordinate necessarily "changing".

I Hope this helps to solve the problem.