Unable to import XLSX file

Hello-

Our customer receives an excel (xlsx) file from a 3rd party every month.  We are unable to import data to grid in P4141Z1.  We setup a PD instance for  ONLY 1 user to do the import allowing for 10000 grid lines.  If we do 100 lines it works, 5000 & above it gives sometimes gives a pop with no message.

when we attempt 100 lines:

When we attempt 6000 lines, it gives error and it also opens the Excel file in the background.

How to we import an excel file with 10000+lines?

Thanks,