There could be 3 reasons.
1.) Lalafell players sometimes just vanish the same way players of other races do, either after getting ressurected or after changing gear they are no longer displayed until they change gear again or you relog.
2.)Like someone before me already said, there's a limit on how many characters can be displayed. You were probably just unlucky and it was always the Lalafells which weren't displayed
3.) Ever thought your camera options might have resetted? There's an option with which you can decide on how "high" your camera is supposed to be..and maybe it's so high that Lalafell are BELOW the lower edge of your screen

....4.) Maybe your game is just broken.
If that's the case, reinstalling should help.