I was experiencing a similar issue. jumpy scroll and when you focus on some input while the keyboard is up, the scroll will be erratic and pushes the target input out of the viewport (under header bar).
disableScroll didn't help. It did fix the jumpy scroll but I was still having issues with erratic scrolling on long forms when you tap on input while the keyboard is up.
To fix this, I additionally had to do
Not sure why this was required after disabling scroll.
Hope this helps.