Is "avenging the deaths of other players" bugged?

There’s a Ubisoft Connect mission to "avenge the deaths of 10 other players". I’ve completed the game’s story and haven’t encountered a single other player to avenge, even though I’ve been playing while connected to the internet, and can see other players’ in-game photos on the world map. My PS+ subscription is also current (I have the PS5 version of the game). Is this feature currently broken, or am I missing something?