Asus Zen Pro Freezing in GTA V/other games

Hey guys,

I have a Asus Zen Pro z240icgt - which I'm fully aware is a stupid choice for gaming - which seems to be freezing in GTA V and other games (so far all I know is Sims 4) BUT not games like TF2. It'll freeze for like half a minute and then unfreeze; if I am online, like on GTA V, I'll get disconnected but stay in-game after the freeze.

So far I have tried increasing virtual memory AND... resetting Windows 10... AND putting the game on a USB SSD drive (which is where it 'lives' now).

Any ideas on why this is happening?