Mine just would not boot without a warning that my DDR sticks were in the wrong slots or their settings were wrong. Neither applied but the only option was to shut down. Not possible to enter the BIOS, shutdown the only option. I had to reset the CMOS (didn't need Q Flash) and then manually set everything up.
IIRC it was part way through the BIOS revisions for the Z390 Master that they changed it where you would no longer be able to restore previous version BIOS settings AND it would automatically set optimised BIOS default settings on one of its reboots following an update. That board had dual BIOS's, with dipswitches as well.
I'm guessing that they had enough complaints / concerns from people to bring in those changes. That is what surprised me to note when you first mentioned of restoring your BIOS settings, I automatically didn't think of trying that due to the Z390 changes noted.
Back to manual input from now and restore the fan profile only.