My Lovely Wife (2023)

Both couples end up platonically living together at the beginning (as a contract couple vs. step siblings) and then fall in love, only to (wrongfully) learn they may be biological half siblings.

Both drama- the main couple were childhood close friends. The FL father remarried. The evil stepmom brought in a daughter… the stepmom bully the FL and the story goes from therer…

Both MLs are wealthy and have trauma-related mental illness and FLs are their employee or contract wife. The two fall in love, and the FL helps the ML begin to heal. Both MLs have complicated relationships with their grandfathers who raised them after their father's deaths.

Both are mini dramas with a wealthy, ill (mentally vs. physically) ML who becomes involved with the mute FL. Both have scheming, evil relatives who cause problems for the couple.