Both Filipino dramas are made by the same company. They have a light vibe but unexpectedly deal with heavy topics.

Both of these are webseries/mini series set in South Korea. They also both handle LGBTQ+ relationships.

Both are about an LGBTQ+ couple living is South Korea.
Both have the actor Kang In Soo portraying a main character.

Both are LGBTQ+ drama's set in South Korea.
Both of them also have an actor, Jang Eui Soo, in common.

They are Chinese costume drama's that focus around the two male lead characters, who are in a beautiful bromance. Both are based on LGBTQIA+ books, but were censored because of the way China works.

Made in Thailand, both of these series deal with a medical student and an engeneering student falling in love. There is friction, and the med student ends up catching the eye of yet another guy, making the engineering student jealous.
Both also have a token of love, if you will. In My Engineer, it's roses and other flowers they use to communicate their feelings. In My Gear And Your Gown they have a pair of earrings they share.

As they are both Chinese series, they have the language in common.
They also have a similar vibe, with the costumes being the same kind of fashion.
Both have two male leads, one of whom is a doctor, facing off evil and investigating cases.

Just like Pornographer, Sei no Gekiyaku has some very mature contents. Both are made in Japan and concentrate on an LGBTQIA+ relationship. You could also (in my humble opinion) say that, in both Pornographer and SNG, one takes advantage of the other, leading to a physical relationship and feelings that begin to grow.

Both are Taiwanese BL series, with multiple LGBTQ+ couples. They both have an MC who's an orphan, and another guy who wants to take care of them.

They are both Pinoy BL series, and both deal with real problems people of the LGBTQ+ community face in a realistic way.