I had the opposite problem, where the players were invisible but their guns were not. It happened in 5 of the matches I played today, twice in QP and three times in Rumble. It's not easy having a ranged fight when you can't see the enemy's head.
Right!? We've encountered all sorts of glitches just recently. Just had a funny one where my wife's hunter chucked a titan pulse grenade, we both stopped and had a "huh... how?" moment. I think there actually might be a few database errors introduced possibly cross save issues??? Who knows, hard to tell without having eyes on any code or data.