Ming Yue Ji Jun Xin (2022)

Both are historical dramas centered around investigation/mysteries. Both FLs actively pursue the ML.

Both are historical mini dramas in which the leads are attempting to solve a seemingly supernatural mystery.

Both are historical mini dramas in which the leads are investigating a murder mystery together that connects to the past massacre of one of the lead's family.

Both are short length historical dramas whose plots involve a spooky murder mystery.
.......................................................................