We all remember this moment when Kuvira left with Baatar Jr Zaofu? I think after it happened Suyin had a emotional breakdown and just kneeling there and cried, maybe got a panic attack. I also headcanon it that Suyin started after it to fall in a depression, on sometimes this heavy that her husband had to spend hours with her in the master bedroom, comforting her or he did her work because she hadn't the energy for it. Besides it, she drunk often to much, her emotions let her feel nothing or to much. Especially after the events from season 4, this nightmare continued cause of the feelings she still had for Kuvira, not knowing if she will ever see her again. So I also think that's why Kuvira is back after Ruins of the Empire. That Suyin payed for it, begged for it in front of Zhu Li to let Kuvira go home. We all know that Su ignored Opal's question, why she still have a soft spot for Kuvira. She even ignore Baatar Jr that he doesn't want to see Kuvira again.