[Solved] In-game mesh help: sims hold objects too low

Hey all! I'm new to making CC and this forum has been absolutely invaluable for my learning process, so thank you so much to everyone who answers questions here!

I'm almost done with a full-body outfit mesh. Everything's looking good, except whenever the sim wearing it holds something, they hold it way too low like this.




Kinda funny with the guitar, but it happens with every object. They always hold whatever it is with arms fully extended, down by their waists. It only happens with this outfit.

I thought I had all the weights and bones and stuff right but idk. Here's the blend file and here's the package. 

Thanks