Ok, so if there is a problem with None you can try to put in a Delay before you execute the Timeline.
This changes the execution order to schedule this after everything else is ready.
Either to check for execution order problems to refactor things, or just to keep the Delay in if it works and if nothing else breaks.
I guess you do not call this all on construction of something. At least at BeginPlay or after?
Regarding your Ease function I think this will not work as intended.
You want to ease between initial and final location and not between current and final.
If you use the timeline for that, you probably want to create your own easing or even bouncing, since you got full control over your bouncing curve.
I have described this here already (Just look for a comment with a timeline screenshot)
https://answers.unrealengine.com/questions/457815/blueprint-moving-object-different-distance-each-ti.html
hope this helps 
Marooney