If an anim montage is played on the character on server the anim notifies may or may not trigger.
They are only triggered reliably in the owning player’s instance of the game, if the player himself is not listen server then the anim notifies are ignored in random manner.
Setting the anim notifies to branching points increases the probability of it triggering but its still misses some times .
The above is in context of play in editor scenario , haven’t tested it on a packaged game yet.