They've been exposed for NOT lipsyncing on so many occasions for example: Jungkook singing while jumping and starting to laugh and the singing stops when he's laughing also i don't remember on which concert but while Jin was singing Jungkook decided to scare him and Jin screamed and yet again the singing stopped also when Yoongi's mic/earpiece stopped working mid lyric during mic drop and Joon and Hobi sang his part there's so many other examples but these are just the first ones that i can reme