Hi Jainil,
Greetings from Syncfusion.
We have considered the reported scenario as a bug and logged a defect report for the same. The fix for the reported scenario will be provided as a custom patch. Please find the below feedback link to keep track of the reported scenario.
Feedback link: https://www.syncfusion.com/feedback/41796/the-excel-export-filename-is-not-proper
If you have any more specifications/precise replication procedure to be followed, please add it as a comment in the portal.
Regards,
Swetha