No, that's not a usual boot sequence.
Danny, may have a point - the motherboard may not be supplying enough juice to components in standard mode. Game mode may well be juicing it enough to replicate stability - well it is stable in game mode at present.
It may be worth adding the 4 pin - may make a difference to power distribution - not just extra raw oomph - as this may help smooth things out.
But it's late - i need to hit the sack. I recommend you do the same.
Windows will have a load of updates to do - i would force the issue and let it update while you sleep (you have smoke alarms, right?

).
We can resume tomorrow - and hopefully resolve it one way or the other...