Yup ... still a problem. I assume you cant get the last gnome on the great white north map where you have to fall off the cliff and the gnome should be in that cave. I struggled with it too and tried all kinds of things. What worked for me wasnt just a hard reset but to unplug the xbox. I left it unplugged for like 5 minutes. then started it back up started a private match from the plant side, switched to the zombies. I think my settings were no plants, regular zombie team, crazy difficulty, and zero gravity and the super fast run speed thing turned on. And it showed up.
I have no idea if this will work for you but i hope it does because i was ready to kill the thing too ! Good Luck
