The two dramas are an inversion of each other - one is a real world person entering the world of a historical game, the other is a person from a historical game entering the real world.
Both are short (short drama vs. short movie), fantasy/historical genres, and have the same actor and actress as the main couple. Both FLs were the MLs first love, and return to him with a different face.
Both are short (drama vs. movie) and are about a real world FL entering a fictional historical world with VR elements and trying to survive/return home. Both MLs are royal and initially antagonistic to the FL. The same actor plays the ML in both.