Im having the same issue with 4 3.5" 4TB HDD's, I have not tried to power them on one after the other due to the way they are setup, however with 3 HDD's everything works correctly and with 4 HDD's it simply doesnt boot. Did you come up with a solution?

Hey, I have the Nanopi M4 with the SATA hat running Armbian and having booting issues. The Nanopi M4 refuses to boot with four 3.5" HDD's connected at once, if i remove any of the four anmd only use three HDD's it boots just fine. The M4 is being supplied with 12v with up to 8A available. I hav...