Digitigrade leg from Blender 2.79 Broken in Blender 2.8

So, I followed this tutorial to make a digitigrade leg:

An it has worked fine for all the rigs I have made with it. Like this one:

That is, until I opened it in Blender 2.8:


Somehow the leg bones are detaching from each other. It also does a bit of weird jittering when you move the IK bones. It also does this on all the other models with this leg IK that I have opened in blender 2.8. All the other IK constraints work normally. How should I fix this?

Ok, I did some research and apparently this is a bug relating to overlaping IK Chains:
https://developer.blender.org/T61621

My workaround is to set the foot bone’s IK chain to 1, so they don’t overlap.