We have tried to export the data into excel in the Virtualization enabled Grid at our end. It is working fine and exporting all the Grid data. Please find the below sample for your reference.
To validate further about the issue, Please share the below details,
1. Share the complete Grid code
2. Share the Package version which you are using in the sample.
3. Share the issue reproducible sample (or) reproduce the issue in above sample.
Prasanna Kumar N.S.V