I found following Q&A:
Q: Cannot print two-sided in Excel, but can in Word?From this Q&A, the reason is following:
https://answers.microsoft.com/en-us/msoffice/forum/msoffice_excel-mso_other-msoversion_other/cannot-print-two-sided-in-excel-but-can-in-word/1dd47955-6f66-4f91-8b9c-8513d572c068?auth=1
Excel keeps it printing configuration on each sheet.
If you want to print all sheets with two-side configuration, you should check and unify all printing configuration that using two-side printing.