Could not boot from SD card after flashing system files to NVMe

Hi,
I am using Jetson Xavier NX Developer Kit and ubuntu 20.04 with JetPack 5.0 flashed by sdkmanager gui.
I want my board boot from SD card when it is inserted in, and boot from NVMe drive without the card, which works well with JetPack 4.
My problem now: even newly flashed SD card just boot once, then NX system will automatically boot from NVMe.
Did I miss some steps when flashing? Or do I need to modify some parameters in configuration file?
Please help me. Thank you.

Have you ever checked the boot log over jp4.x?

I don’t think what you said for jp4.x behavior is correct… unless you changed the boot order.

Thank you for your reply.
I followed the instructions from internet to change the boot order before I installed JetPack 5.
What to do if I still want to boot from sd card or from nvme with JetPack 5? Could you tell me how to set the boot order? Thank you.
Now I can only boot from nvme even if sd card newly flashed.

What instructions did you follow?

I remember that I copied some files from sd card to nvme…

Hi, I do not know much about the deeper level operations on nx board.
My problem (since I installed JetPack 5):
If I flash nvme drive, I cannot use sd card for booting even if it is newly flashed. I have to erase nvme before booting from sd card.

Anybody and any ideas, please help. Thank you.