Opting out of the built-in field list dialog, we're trying to implement a field list beside the table. We're also dealing with large datasets so we previously needed virtual scrolling which worked great. However, it seems the two don't work great together. When manipulating fields in the field list, and then expanding or collapsing rows in the pivot table, the data just gets lost.

Note that I've followed the minimum steps to implement the static field list along with the pivot table. Then tried the dedicated field list section under Virtual Scrolling - and it still did not work. The example in StackBlitz there exhibits and reproduces the same issue while the preview in site does not.