on march 15th (around 18:00 (CET) ) a brief bug was noticed concerning special:watchlist on fr:wikipedia.
Steps to Reproduce:
open a diff of your watchlist, reload the watchlist.
the article title stay in bold.
the article title should not be bold anymore.
the bug was "resolved" 25-30 minutes after I first spotted it.
Today (march 17th) around 13:30 (CET) I noticed the bug was strinking again. This time, it lasted around 20 mn.
We already saw it every couple of hours. The API query for unread edits returns all rhe bold ones all the waiting time.