There is a bug on Timeline custom events.
If, the output “Update” not be used, the timeline dont fire the custom event trackline.
Simulating:
- Create a Blueprint
- Add timeline node
- Inside timeline node, create a track event.
- set time 0.05 and value 1 (1 tick each 0.05 seconds)
- check autoplay, last keyframe and loop
- add some node to be fired on this ouput.
- Observe only will fire if u link another node to update output.
This is still true in 4.12.5. I had to add an arbitrary node to the update pin (delay(0)) in order for the Event Track keys to fire.

Hi jessome,
I tested this on my end and it appears to be working as intended. If you are experiencing a potential bug, please open a new answerhub post in the bug reports section. In this new answerhub post, please include what steps you are taking to reproduce this and whether or not it occurs in a clean, blank project with no additional content. I am closing this thread as outdated.