FFXIV crashing during dungeons

Every now and then I'm getting random crashes during dungeons. The first few times that this happened were a few weeks before 2.2, and now it's happened again today.

In all occasions, the game's graphics would look "weird" before crashing altogether. Either certain details and effects would be missing (like no blue/red circles around targeted enemies/allies), or the game would look fine at first and then have these huge green triangles popping up on the screen before crashing.

I'm on PC, and I considered it being a potential hardware problem. But since it first happened I've yet to encounter any similar situations in other games, nor during normal PC usage, and not even in FFXIV itself outside instances (like I said, it's only happening in dungeons).

Has anybody else had similar issues before?