I've only encountered midnight mode at late night so there's no bugs regarding that part (though at first I thought my game was bugging out and was confused why the game changed visuals and npcs when I started a new save in the morning). Although, I did just encounter a minorish bug, I'm at Cain's normal route food tasting scene and I picked the second dialogue option and it resulted in getting "Loading Error, Failed to Load: audio/bgm/summer's%20final%20station%20(%E5%A4%8F%E3%81%AE%E7%B5%82%E7%9D%80%E9%A7%85).ogg" I had to save after finishing the scene and close and reopen the game to get the error message to stop appearing. Also, you're welcome, the game's lovely, so it deserves so many more kind comments!
You're welcome, glad my bug reports can be of help! Also just encountered another bug, in Bern's normal route's post-credit scene, when you're about to show him "your ideal man"(I presume a photo of Bern), I received the error "Failed to Load: img/animations/Flash.png" preventing me from finishing the scene.