Grid becomes empty after changing inner tabs with Virtual Scrolling

[marceloavf]

Bug Report

Package versions:

devexteme version: 20.2.4
devextreme-vue version: 20.2.4

Steps to reproduce:

1. Wait for the data to load in the DxPivotGrid.
2. Scroll horizontally to activate virtual scroll changes (it also happens when there is a lot of data vertically)
3. Go to another tab (about)
4. Then come back home, you will see it blank, but if you scroll in a little it'll come back.

https://codesandbox.io/s/relaxed-voice-m1hwb?file=/src/components/HelloWorld.vue

Current behavior:

When changing tabs, data disappears until you scroll the table again.

Expected behavior:

Expected to be able to see data even when changing tabs, from where we were.

Screenshots:

When enters the page:

When changes tab after virtual scrolls actives:

[marceloavf]

One way that I found to bring it back was to call repaint() method after it get back from keep-alive instance with activated lifecycle hook.

[marceloavf]

updateDimensions() also seems to work and performs better than repaint every time.