So it happened to me again and I thought it was a problem related to coming from stealth, as we already had discovered on this forum.
But it's not even the case cause my main character who was in stealth attacked one of the minotaurs while the others were waiting at a distance in plain sight. Then when I brought everyone in, 3 of them got into the same sequence.
Then after I moved and attacked with one of them, a click on the space bar went directly to the first minotaur. And it didn't end there, if I hadn't clicked on the portraits of my party members, every single turn it would skip 2 of my companions turn. This needs to be addressed because it can ruin a combat completely.