reServer Industrial J4012 - deleting boot options is not persistent across reboots

I have reServer Industrial J4012. But deleting boot options from the boot maintanance manager menu does not seem persistent across reboots of the device.

More specifically I am trying to remove the boot options for PXE, HTTP and Shell. See the screenshot below:

However when I commit changes and reboot the device, the boot manager still shows the boot options. See screenshot below:

Additionally I also want to disable all booting from external devices like USB.

Can someone help me how to achieve this?