They flat-out don't do anything on Chrome desktop, and on my phone they're in the worst possible spot so you end up mis-clicking the user's profile page half the time, plus they're kinda in the middle which isn't good for left or right-handed thumbs. I'm a web developer and I'll happily contribute the fixes needed if somebody wants to let me at it.
Mobile is being worked on already. They do work on Chrome, I suspect it is a problem on your end.