Funky artifacts including jagged black triangles on screen
sounds like VRAM that's unstable (too low voltage, too high clock, too tight timings, etc)
I bet if rip the plate off it says Hynix on those chips.

gpu-z is reporting Samsung RAM but it must use a bit of Hynix for something.
OMG stay away from MSI and cards with Hynix RAM or you'll end up so butt-hurt your asshole will drag on the ground behind you as you walk.
what the problem with the hynix all my gpus are hynix and they doing very well, support the most tight timing and clocks and very stable, i got recently 2 samsung and what a pain to make its stable.