My laptop is a Lenovo Yoga 720 15IKB that is set up to dual boot between Mint [Linux] and Windows 10. The system came with Windows 10 pre-installed and the partition Windows 10 is on was shrunk to make room for a second partition for Mint Linux. The boot order is set to Ubuntu then Windows. The Ubuntu Boot menu allows booting into Linux or Windows.
The problem is that every time the system boots, the boot order has been rewritten so that Windows 10 starts up and there is no choice to start up the Linux OS.
In order to boot Linux, I must first allow the laptop to boot up Windows, then access the UEFI from the Windows recovery applet, change the boot order so that Ubuntu [a.k.a. Mint] is first and Windows is second, save the changes without exiting the UEFI setup utility, then exit without saving changes. The computer then continues to boot up with the Linux Grub menu that allows me to select either Mint Linux or Windows. If I try to exit and save changes instead of the two step process, my changes are ignored and the system boots directly into Windows 10. The next time I enter the UEFI setup utility, the boot order has been changed back to Windows first and Linux second.
On top of this, rebooting from Linux fails. The system shuts down correctly and then fails to start up again. A full power cycle is needed to restart the computer which results in the system booting directly into windows.
I have tried using EasyUEFI from Windows. It cannot alter the boot order because the "memory is read-only" even when run as the Administrator. From Linux, efibootmgr shows the boot order as Linux then Windows.
It is unclear exactly when the boot order is getting changed. It is not clear whether Windows 10 is changing it or the Lenovo firmware.
My question is basically, how do I get my laptop to use the Ubuntu efi so that a menu appears with a list of the possible boot choices and default to Linux if none is selected?
Laptop: Lenovo Yoga 720 15IKB OS1: Windows 10 OS2: Mint 19 UEFI App: InsydeH2O Setup Utility