There seems to be some issue on using labels within the last elseif branch. The last label before the merge doesn't get rendered. See following code . Result happens on the plantuml release version and the online version:
if (condition A) then (yes)
elseif (condition B) then (yes)
(no) elseif (condition C) then (yes)
(no) elseif (condition D) then (yes)
As you can see the arrow label after Text 4 doesn't get rendered at all.