Sorry for the late reply. I installed Android system web view, but where is the "default system provided one"? It's not an app on my device. ThanksAPPS that have webviews in them shows slow scrolling and bad touch response?
I received same issue twice after fresh installing this ROM, I was able to resolve this issue by installing Android system web view from playstore and disabling the default system provided one.
Disclaimer : my observation might be flawed. But it did the trick for me.