It might be a better idea to have each object be an actor blueprint and have the movement logic be in this bp instead of in whatever bp is doing the spawning. They’ll each start running their own instance of the code whenever they spawn and you shouldnt run into any issues with your timelines.
This will obviously make finding your spline a bit harder in each of those instanced object (I’m guessing you’re using level bp right now), but you should be able to grab that spline from the level if you use a “get all actor with tag” node, as long as you give your spline a unique tag and then hooking up the array it gives you to a “for each loop”
, which will only run once if no other actor have the tag you specified in your search.