I was going to use DDU when I realised that I actually use two GPUs, Intel and nVidia, one monitor each. I deleted both drivers/profiles with DDU and now I'm using just nVidia. Let's see if that solves something.
Also, I have deleted MSI Gaming APP, because sometimes the app makes my desktop icons to have some flicker, so it may be causing some troubles with the theme, who knows.
Seems like there's been no problems this week, not a single 'black screen' issue this time!! I guess it is misteriously resolved now. This weekend I will install again MSI Gaming App and see what happens.