Normally a stock bios should work, There’s normally nothing important for operation that has to be kept from earlier versions.
In addition your board has 2 bios chips with possibility to switch. Did you overwrite both chips? If not try to get a dump of the other bios, you might still have your data…
Instead of updating different versions I’d propose to dump the current bios and to compare it/ bios region to stock. Try using flash programming tool in ME System Tools v9.1 r7 from
Run as administrator Fpt(w(64) -d spi.bin
This will try to dump the complete firmware into spi.bin. Since you flashed stock bios your descriptor should be unlocked, should/might work.
Post/attach spi.bin