Thread:NoWayThisUsernameIsAlreadyOwnedBySomeone/@comment-26561761-20160326050417/@comment-26143371-20160516195801

I've noticed the tabs aren't very reliable; pages always load without them, and usually the sections collapse into tabs after a few seconds That's normal, just like the navboxes (which need a bit of time to collapse), the content is stored "untabbed" on the page and then converted by the JavaScript after the page has loaded. If it was made differently, users without JavaScript (mostly mobile devices) wouldn't be able to to see anything but the default tab.

but sometimes they don't. I experience such issues from time to time too. As far as I can the the only reason for this (and the one that applies when it happens to me) is that the JS in question has not loaded, which is either caused by a bad connection on my side or by some problem on wikia's side where JavaScript isn't delivered properly.

According to w:Thread:1041278 there have been some issues with tabbers and other JavaScript on wikia's side. So if you've seen this recently it might have been that issue.

If you find cases where tabbers are not working, but navboxes are, then that would really be worth further investigation because that really shouldn't happen.

Problems seem to be most common right after a page has been edited You mean you edit a page, save it and the script isn't working, but after a reload of the page it does?