CSM keeps enabling after cold start

I have a Steel Legend B450 motherboard. I tried to disable CSM and enable secure boot. It works fine and I can boot into Windows 11. However, whenever I shutdown the computer and restart 20 minutes later, CSM will enabled automagically and secure is disabled because of that. If I reboot the computer without cutting off the power, the CSM and secure boot setting will remain the same. I don't think there is any issue with the bios battery as all the other settings in the bios did not reset to default.

I have tried to update the bios to 4.6 and 10.08, that didn't fix the issue. I have checked that my GPU card supports UEFI. I have swapped the keyboard and mouse. I have tried unplugging the network card and headset. So I don't think there is any legacy device that might have caused the CSM to re-enable by itself.