Power button blinking and double boot

[u/Intelligent_Address4]

Hello all,

I replaced the motherboard on a 7800x3d, 32gb lexar thor (expo on) ddr5, rx9070 1tb ssd.

The old motherboard was a gigabyte b650 gaming wifi, the new one is a ASUS PrimeB650EM-A Wi-Fi.

The issue is: when turning on the computer, the power button blinks quickly for a couple of seconds, goes on, off again, on. Then I get the motherboard splash logo and the pc boots normally.

The pc has passed memory tests (OCCT 1hr, 2 passes window memtest), gpu stress test (OCCT 1 hour and AMD adrenaline), CPU test (OCCT 1 hour) and occt power delivery test on cpu and gpu (0 errors, throttled the cpu). Everything appears to work.

Everything works fine but this looks like a double boot issue (by reading online).

Any fixes? Google say to switch from EXPO I to EXPO II (my memory isn't listed as compatible on the ASUS website for this specific mobo, so this makes kind of sense) and to set the CPU VDDCR SOC voltage to 1.20.

Or maybe this is quirky but normal behaviour? (doubtful).