I have the same problem. My PC just freezes to the point that it requires a forced restart. Drivers are up to date (RX 580), temperature during gameplay is within the limits (CPU at ~60C, GPU at 75-80C). It only happens in GW2. No clue what triggers it, ran a few diagnostics on RAM - fruitless.
It is REALLY sad this happens, and as I've checked the old forum threads, there doesn't seem to be a solution. People just dropped the game.