I tried to delete a uplicate topic on
https://pt.wikipedia.org/wiki/Wikip%C3%A9dia:Contato/Fale_com_a_Wikip%C3%A9dia
and got an error message saying something like insuficient permissions, however I have sysop rights on that wiki. I tried again a few seconds later, loading the same page with uselang=en in the url, and the topic was deleted, without any error message.
These are the logs:
https://pt.wikipedia.org/w/index.php?title=Wikip%C3%A9dia:Contato/Fale_com_a_Wikip%C3%A9dia&dir=prev&offset=sh8vwja9exe5dm54&limit=3&action=history