When a vandal reverts your own edit on your own user talk you get two notifications if you have chosen in your preferences to get notification for "Edit revert" and "Talk page message".
It's actually working as expected but IMO user talk page revert of your edit should only trigger "talk page message" or "edit revert", not both.

An example edit https://id.wikipedia.org/w/index.php?title=Pembicaraan_Pengguna:Stryn&oldid=prev&diff=15611109