as you can see from this jsFiddle the "top" value provided from the "ScrollVertical" event callback is different each time you scroll down until the end of the scrollbar.

I am trying to build a "virtual scrolling" behaviour, but Tabulator doesn't give to me the correct scroll position.

const table = new Tabulator("#example-table", {
    height:"300px",
    layout: 'fitColumns',
    
    data: data,  // a some-hundreds long list of objects...
    rowHeight: 40,

    columns:[
        {title:"Name", field:"name"},
        {title:"Surname", field:"surname"},
    ],
});


table.on('scrollVertical', (top, dir) => {
  const dirStr = dir ? 'up' : 'down';
  console.log('scrollVertical', dirStr, top);
});

"virtual scrolling" is for me a form of "pagination":

1. I ask to the server the number of table rows (e.g. it responds: 1000);
2. I fill the table with that number (1000) of empty rows, so the scrollbar is enabled;
3. User moves the scroll-bar to the middle of the table;
4. I am subscribed to the "ScrollVertical" event, so I get the "top" position (now is not reliable!) (I can easily calculate the scroll handle is, in my example, at the 50%)
5. I ask to the server the rows I need (e.g.: from 480 to 520)
6. I use Tabulator function to replace the relative empty rows (480..520) with the ones retrieved.

But... The "top" value of the "ScrollVertical" event callback is not reliable at the moment :(

Does someone faced (and solved) the same issue?

I opened a bug to Tabulator team: