Yeah... mostly over parts of their personalities that clash!! He's stubborn, a closed book while she's highly strung at times and sensitive to his bad moods. It gets worse when they have to be away from eachother for long periods. Catman is an extremely stubborn outsider, and it took a good while for him and Lyse to reach a comfortable place of sharing their thoughts etc. After EW he lived basically off-grid for a few years on the Island Sanctuary and didn't even tell her RIP.... Lyse will try to shoulder a lot his burdens alongside her own and feel enough guilt for them both. She'd apologise to him faster for something she didn't even do.