So I think I narrowed down the issue and came up with a workaround. First this issue has nothing to do with HDDs plugged in as far as I can tell. I actually found an older post where someone else ran in to this exact issue:
https://rog.asus.com/forum/showthread.php?55925-Refuses-to-display-post-bios-windows-boot-on-display...The above post was right on the money with this problem which is encountered with DisplayPort (DP) connection only in native UEFI mode (CSM off) and does not appear to happen with HDMI as I tested HDMI with the same monitor and it did display the ROG boot logo each time. My monitor is the Acer Predator 4K 144Hz (DP 1.4 & HDMI 2.0) and to get the higher refresh rates I need to use DP so HDMI is out of the question. I do not know if this is UEFI issue in the board BIOS, GPU firmware or a combination, but to get the video working every time on POST I have to enable CSM even though I'm not using legacy boot. It's interesting that video does work if I press the hard reset on POST with CSM off but it only works once and then reverts to no signal on consecutive boots. CSM (which is not enabled by default in BIOS) does output the video over DP during POST on this higher resolution monitor, maybe because it lowers the resolution? I tested a low spec (1920x1200) Dell workstation monitor with this board in native UEFI (CSM off) and this problem does not occur so it is something related to higher resolution and DP specifically.
I did not run in to this issue with the same GPU+monitor on my previous build (Rampage IV Extreme) Dark Hero replaced as the old board did not have native UEFI and only came with CSM boot.