I have a similar issue, but it isn't all sound. It's strictly sound from my modded bits, like keyboard sounds, background sounds, and sounds that happen when I open a tab. I can hear things like YouTube, and the Spotify app just fine on my earbuds, but none of the mods that I really want to hear.
I've tried another pair of earbuds; totally different maker, make, and model, and had the same issue.
It's not a huge deal since I can still hear everything else, but I wanna be able to hear the lovely keyboard sound I picked out!
If it helps, the earbuds I've tried are both Bluetooth, and they were Google Pixel Buds, and Sennheiser Momentum TW's.
Thanks in advance!