Blender Version
Broken: Blender 2.8
Worked
Short description of error
Increasing the bending value on both the stiffness and damping making the cloth simulation wacky. increasing it on the stiffness gives it a permanent noise effect and increasing it on the damping makes it messy. The bending value could get a lot higher in 2.79 without it freaking out.
Exact steps for others to reproduce the error
You need to increase the quality steps for the simulation to be stable if you have complex meshes or demanding settings. This is not a bug.
@Sebastian Parborg (zeddb) Increasing the steps helped with the bending on the stiffness but not the damping. I used much more complex mesh in 2.79 without having to increase the quality steps. Are you sure there is nothing wrong with 2.79 being able to simulate this mesh at a lower quality step than 2.8? And even after I increase the steps, it doesnt stop it from freaking out when increasing the bending on the damping.
The issue is that bending didn't really work in 2.79 before the new fixed cloth code got merged. See this video for an example:
https://vimeo.com/202503234
First it shows the old 2.79 behavior and then the new and improved 2.8 behavior.
As you can see the bending didn't really do anything in 2.79. So now when it works, you have an easier time to get the simulation unstable as you have noticed.
Most simulation things in blender allows the user to shoot themselves in the foot so to speak. You can input values that makes the simulation inherently unstable.