Description: My older T530 runs Ubuntu, Ubuntu LTS, Fedora and Windows 10 Pro. I recently booted into Windows for once in a while again to check some things. It installed one of the update batches which are now default, nothing suspicious to me since this machine is configured to also receive Insider updates. I turned it off, then tried to wake it up a few days later via WoL+SSH. No reaction. I went to the machine, powered it on, looked at the boot options: No Ubuntu and no Fedora, just Windows! No other boot devices for recovery like HDDs or USB devices either!
That has not happened to me after familiarizing with UEFI.
Further observation: The boot options menu looks different from what I recall and there are no USB devices there. I can't remember if the menu was this way before, but after carefully scrolling up and down the entire (short) list of boot options, enabling entries, rebooting and updating the to latest firmware update from the Lenovo website (I have a suspicion that Windows installed an older firmware update, this was almost a year old and I recall updating it earlier this year or at least in fall last year, not summer) I still can't find any other useful option to boot from. The Fedora entry was enabled but didn't work and sometimes did not appear in the list, Ubuntu entries don't show up at all when enabling them.