Downloaded the full jChartFX package a week ago (not licensed v7.2.5289), built a very simple gauge with animation enabled, works mostly. Notice in my script the needle value should be right at 82. Every time I refresh the page the needle varies a bit. It seems to just pick a random value around 82. If I hover over the needle it may be 79.0 one time, 80.95 the next, then 81.1...what the heck?
I noticed, if I turn off animations, this doesn't happen, needle is exactly at 82 every time. I notice on slower devices like a phone (android), the need stops even lower, so around 60 - 70.