Scroll to index duration problem

[KropVO]

I set the scroll position to 1000 out of 1500 and the scroll time to 1 second. But in fact, it takes about 10 seconds to scroll to such a position.
And if you put the scroll on the 20 position, then the scroll will be around 100ms

[vnt32]

please refer to this thread #44 for more detail.