Need to investigate root cause here, but if parsoid read views are enabled and (say) the following is on the page:

-{T|en:Pig Latin Test (en);en-x-piglatin:Pig Latin Test (pig latin);sr:Pig Latin Test (sr);sr-ec:Pig Latin Test (sr-ec);sr-el:Pig Latin Test (sr-el)}-

The title is shown as:

en:Pig Latin Test (en);en-x-piglatin:Pig Latin Test (pig latin);sr:Pig Latin Test (sr);sr-ec:Pig Latin Test (sr-ec);sr-el:Pig Latin Test (sr-el)

That is, the -{T|...}- seems to be being parsed and someone is calling the appropriate method in ParserOutput to update the page title, but rather than actually selecting the proper title based on the current variant, the entire string is being made the title.