I loathed the ending of Mr Queen, also. It felt inexplicably like the audience was being gaslit. We were shown a couple deeply in love and connected, and I couldn't believe the writers expected us to buy that being separated was no big deal and they were both fine with it. Normally I dislike sad endings, but it would’ve been better for the drama to just end sadly and acknowledge how heartbreaking the situation is, rather than painting it as a happy conclusion.
Tale of the Nine Tailed kind of went downhill overall but it was still good, but the last episode ruined it. Like I said above, normally I hate sad endings, but in this situation it would've been better if Lee Yeon stayed dead. Everyone was moving on, keeping his memory alive and also finding their own happiness, just like he wanted, but they had to shoehorn in the perfect "happy ending" tied up with wedding bells and a pretty bow. His resurrection made no sense, and I hated that they sacrificed Lee Rang to do it, even though he was finally happy after a lifetime of pain and trauma.
Strong Woman Do Bong Soon had a weirdly dark ending! It was totally fine except for that very last scene, it made them both look unhappy and left it on a sour note.
Color Rush was excellent, I highly recommend it, but the last episode felt too quick and abandoned several plot threads. Part of what made the story so compelling was that dark undercurrent between the boys, and it was suddenly all peachy and sweet with no mention of the potential dangers.