Question Only one monitor displaying upon startup

[SH Gaming]

So I have never had this problem until yesterdsy. I swapped my components into a new case yesterday and I've noticed only one monitor out of my two ( three if you count the elgato capture card) but when windows is loaded in to the password screen, the monitor displays. I do have a DVI to HDMI adapter because the one DVI cable is too short. The other DVI cable is plugged directly in the GPU. What would cause the problem now and not have the problem at all for over 2 years? Also the monitors are older monitors so I can't connect directly with an hdmi cable.
Mobo: as rock b450 problem
Processor:R5 2600
GPU: MSI RX 580
RAM: GEIL 16gb
Case: Lian Li Lancool 2

 

[SH Gaming]

I should also mention that games like Aim Lab and Gmod runs on the monitor that displays upon startup and not the main monitor that I use (the one that doesn't display upon startup.)
(The monitor that doesn't display upon startup says "Power Saver Mode" when Windows starts up)