Question Monitor doesn't turn on, on first boot, only after I restart..info inside

Habbasi

Honorable
Oct 15, 2013
58
0
10,530
So I've googled this a bit and the only concrete thing I've found is it could be a monitor issue or a PSU issue. I heavily doubt its a PSU issue as it is only about 2 weeks old whereas the monitor is 6-7 years old.
Specs:

Monitor: iiyama ProLite GB2488HSU
GPU: Aorus 1080 ti
CPU: i7-4770k
RAM: 16GB KINGSTON HYPER-X BEAST DDR3 2133MHz
MOBO: ASUS® MAXIMUS VII GENE
PSU: Super Flower Leadex 3 Gold 650W

The reasoning for the new PSU is that my old rmx850 died about 8 months ago and I have only just gotten around to fixing it, I have also ordered a new CPU, MOBO and RAM.

To the issue itself:
The monitor does not display output if I don't turn it on whilst booting the pc up.
To be more precise:
If I turn the monitor on and the pc on at the same time, I have had no issue as of yet. However, if I don't turn the monitor on and boot the pc up, if then say 10 seconds later I turn the monitor on, it shows only a black display with a little orange light where the successful blue one should be.
I am connected using a DP cable directly into the GPU.
Any help troubleshooting or figuring a fix would be great. My new parts should arrive by the end of the following week so I can try those out to see if there's anything wrong.
I do plan to upgrade the monitor soon anyway but need to up my budget a bit first.
Thanks