Anim notifies are not guaranteed to be fired
Good explanation by Vaei:
“Don’t use notifies for important events. A lot of the time they simply don’t fire, you’ll start seeing then when testing game in actual production. Setting to branching point notify ensures they always fire. However branching point notifies don’t fire if there are 2 on the same frame, especialy common when its the start of a montage. Use my task node/plugin instead, it basically looks for notifies of a specific type, caches the time where they should play, and starts a timer, and broadcasts an event”