Comment 28 for bug 1734147

To this point, I am not yet convinced that there is a bug in Ubuntu that causes this.

For one thing, the issue is far too confused here on this report for me to make sense of what is going on. The included links to Lenovo forums do not appear to me as bugs in Ubuntu.

What exactly is the problem?
What settings are changed in the BIOS and appear to not be saved?
Can your system boot into Ubuntu?
If not, what last appears on screen?
If yes, then what does 'sudo efibootmgr -v' report?

Failing to change things in the BIOS does not sound to me like anything that Ubuntu could have caused; but it also seems like there might be confusion as to how booting works on these systems. When systems are booting in UEFI mode, you can't simply add files here and there on the system and expect things to work -- this is why you have named entries in the firmware (the "BIOS") such as "ubuntu": there is some configuration involved, which can be done using 'efibootmgr' on Linux.

If you can't change time/date in firmware, or any other option that is not boot related, you need to consult Lenovo. There is nothing I can do about those. If you are having issues changing boot entries in firmware, it's possible that it is simply not supported -- the firmware might not allow you to set the ordering; and to disable UEFI you may need to first disable Secure Boot. The best is again to consult Lenovo for help and describe exactly what you want to do. They know how their firmware is supposed to work; and what is and is not possible to do.

Please also try using F12 or Fn-F12 (whatever the key combination is on that particular hardware. I have Lenovo hardware here, but none of the affected systems) to get to the Boot Selection Menu and see if then you can boot to USB or to Windows (if it's still installed) from that menu.

Please avoid using rEFInd if possible, as I cannot provide support for its use. It is known to change settings incorrectly; and that can cause issues on upgrade. The fewer extra changes on a system once it stops working is always better to figure out what is wrong.