I have run across multiple combat glitches, lately.
Today, 1/25/18, at 2:42 P.M. GMT-6, during a war battle, a confused enemy Ouros performed a special attack. As the special animation finished showing the monster stomping on its own team, it started right back up again, but this time showed the monster stomping on my team. The confused Ouros got off two special attacks at the same time, causing me to lose tokens in the war.
Every time I use a Slow effect in combat, the turn order is shuffled so that one or more of my own monsters are skipped, or so that enemy monsters don't show up at all. After one attack, the turn order changes yet again and is completely different from the original or first alteration.
Stunned or Frozen monsters sometimes get an attack, as if they got a second turn. Monsters attacking with an ability that does not grant them a second turn still end up attacking a second time. These things have happened in dungeons, PvP, and wars. It is combat, in general, that is showing these issues.