Question RADEON RX580, ASUS vp28uqg issues.

Jun 7, 2019
Hi guys, recently I've built a pc (first one).
Everything went smoothly at first on my old monitor. Issues occurred once I started running games on my new monitor. Ever since i upgraded monitors, there has been white static flashes on screen, screen splits in half down the middle (one side black, one side running the game) and also green and black screens - never showing lost signal.
Upgraded my monitor from a Dell 24inch standard HD budget monitor to an Asus vp28 gaming monitor (BOTH RUNNING AT 60Hz). This has caused the pc various issues. I believe an uneducated guess is that my radeon rx580 graphics card can not keep up with how many pixels are being shown on the 3840x2160 display, which is a big shock as i thought an 8gb GPU would be more than enough. Is there any short term fixes to the problem? Also i've returned one previous screen as i thought it was a monitor issue originally and they have informed me that their only obligation is to replace one screen, I.E, I can't take it back as I'm past 30 days now. I have video footage of the 'incidents' and can provide if anyone wants a look.