This must be a recent regression:
Seen on Android Chrome
They are not missing, a recent css change pushed them over to the right so they horizontally scroll. I let @eviltrout know earlier today as I suspect his fix to make the avatars tappable may have caused this.
OK I fixed this… the div was set to 100% width, but when a 60px left margin offset was added, it made the div bigger than the 100% width.