"Uncomfortable laughs" refer to laughter that occurs in situations that are awkward, tense, or embarrassing. It is a way for people to cope with discomfort or unease by laughing, even though they may not find the situation funny. Full definition
Instead of feeling like the same thing on a feature film scale, this film was able to take this character and show the audience his personal struggles, while still making a film filled to the brim with uncomfortable laughs. (filminquiry.com)
(Or, hey, maybe they're just uncomfortable laughing along with Jeffrey Tambor right now.) (avclub.com)
If you've got a sense of humor, this book will definitely make you laugh, but it will probably be the uncomfortable laugh resulting from seeing a bit too much of your own inner weasel. (inc.com)