i dont know that mouth dreams are weird (I mean they're kind of weird) but if you want similar pop music mashups Girl Talk are okay to good

Early Dan Deacon might fit "weird" https://www.youtube.com/watch?v=-6gKT3NnE3k but it's more weird pop than feeling "uneasy"

perfume genius might sort of fit the bill in some songs https://youtu.be/Khum88L9R8k

maybe sleep party people https://www.youtube.com/watch?v=ZqzpSiJzL4c

I don't really like Xiu Xiu myself and can't really recommend any songs in particular but they are certainly uncomfortable to listen to

Micachu mite b weird https://www.youtube.com/watch?v=8TRkZpFgJcI