I have had this problem with every patch. It seems to happen less in patch 4 but characters get skipped in combat all the time for me. It is seemingly random. For instance in the beginning ship fight La'zel will miss the fist round of combat about 25% of the time, throughout the game it is very arbitrary. I wish I had a good explanation. It is seemingly random to me. I have had it skip character's turns when sneaking or when walking straight into a fight.
