Monitor blacks out for several seconds on Engine startup and/or Project load

Hi all. I have a very weird problem on my hands and it’s making working on stuff such a pain I haven’t done so for a week or two.

Basically, whenever I startup the engine from the launcher, load a project, run the game in Standalone or run a packaged project, my monitor blacks out and goes on standby for several seconds before popping back on. It’s like my monitor just stops receiving any sort of picture from my computer and goes into standby, then ~5s later gets the image again and starts backup.

This only ever happens with 4.15 (loading the engine and its projects) and consistently occurs every time I do one of the four actions I mentioned above. All other engines and their projects don’t give me this issue.
I’m not sure if there’s some kind of graphical change or something in 4.15 that causes my GPU to sorta black out while it loads the engine, but that still doesn’t make sense to me because:

a) I get the temporary blackout without loading up projects (I don’t auto-load the last project on startup)

and b) I don’t get any kind of message or notification saying that my drivers crashed

So I have no clue what it is. I reinstalled the engine a couple times but it changed nothing, and I’ve made sure I have the latest drivers for my graphics card but it’s still the same.
There must be some weird interaction with 4.15 and my monitor/GPU but I have 0 idea what it could be.
If it helps, the monitor I’m using is a fairly old one (Bush 22" BLED22FHDL8) and my GPU is an Nvidia Geforce GTX 750 Ti.

Edit: Still no clue what it is, but looks like it isn’t a driver crash. I don’t get the black screen when using a HDMI cable for my PC to monitor, it only happens on VGA. And just to be sure my cable isn’t faulty, I’ve tried a different cable and I still get the exact same results.