Question PC doesn’t fully start up on first try, is fine second time ?

Feb 24, 2021
So ever since I built my PC about a year ago, it’s had this issue that when I press the power button, all the lights, cpu fan etc come on but nothing happens, screen stays blank and my keyboard and mouse don’t light up/come on.
However if I hold the power button until everything goes off and press it again everything boots up fine.

I’ve disabled all the fast startup, hibernation settings etc in windows, done a memtest came back with no errors on both sticks, PSU works fine in another PC has does the GPU.

Happened on Windows 10 and still happens on Windows 11…

Any ideas what it could be?