Steps:

1. Got Page/site
2. Switch to Edit mode
3. Add a block, configure it and submit
4. Click Publish later and set time and date
5. Show timeline and hover over event marker icon

Actual result:

There is unnecessary scroll on event tooltip and the arrow is hidden.
http://g.recordit.co/ukyrlZREH4.gif

Expected result:

Maybe we can remove the scroll?