I've noticed that with fastwiki plugin installed and enabled, linksuggest stops working properly:
printing [[ is not followd by popup with list of ns. The problem disappears after disabling fastwiki
I'm also getting this same issue. Disabled fastwiki and it works fine again.
There doesn't appear to be any errors in the apache error log or the inspector console.
I've noticed that with fastwiki plugin installed and enabled, linksuggest stops working properly: printing
[[
is not followd by popup with list of ns. The problem disappears after disabling fastwiki