Hi Grant,
Thank you for contacting Syncfusion support.
We have analyzed your query and confirmed that this is a bug in virtualization mode. We have logged a defect report for the same. The issue will be fixed and included in the month end patch release which is expected to be rolled out in the end of April, 2019. You can track the status of this issue through the below feedback portal link.
We appreciate your patience until then.
Thanks,
Christo