I have a gameplay notify that needs to be reliably triggered whenever a montage is played. I have ran into situations where an montage ends and the notify has not triggered. I know the montage has finished via the FOnMontageEnded callback and it is not interrupted by an outside change to the animinstance.
The montage is quite fast and has a modified play rate.
I believe I’ve narrowed down my issue due to a combination of a fast playrate and non zero blend out time which reduced the weight of the anim seq to zero sooner than the time of the notify trigger.
You could try using a Branch point instead. Think of it as a high resolution notify. (for some reason very hard to place like you want though…)