Both are mini dramas in which the ML (wrongly) believes the FL has betrayed him or harmed his family and he keeps her prisoner. Both MLs are very aggressive and toxic, and there is a SML who appears to like the FL and is trying to remove her from the house where she's being held, as well as an evil and scheming SFL.
Both are Republican Era mini dramas in which the ML wrongfully believes the FL betrayed him and treats her cruelly, keeping her like a prisoner. There is a manipulative SFL who causes many issues. Both FLs become pregnant and miscarry. Both endings are ambiguous as to the ML's fate and the FL's future.