Logan realized he hadn't seen Roman in a couple of days. In fact, he has only heard from Patton.
Who said he didn't know why the other two had isolated themselves. He was on his way to speak to Thomas about the situation, when he heard voices coming from Thomas' living room. As Logan listened in on the three's conversation, he became aware of the situation and thought he could help. That was until he heard crying. He gasped at the sight he saw. Roman was shaking, Patton was comforting a crying Anxiety, and Thomas was just as confused as him.