It needs a BIOS update. Use BIOS flashback to update the BIOS
Look at the sticker on the mobo the last 4 numbers is the BIOS thats on it now
If it's not 3101, you have to update the BIOS
Core i7-7700K (4.2GHz, 4C, HT, L3:8M,Intel HD 600 series , 91W, rev.B0) ALL 3101
Flash BIOS 3201 since 3101 is a beta BIOS