This can be reproduced in the latest build (1.7.02.0004). Not sure if this is an issue or by design.
If you want the same concept to appear on the same line you need to change the row # to be the same.
Tested with build 1.7.04.0001 and the fix appears to be working correctly.
Description
the items that are entered into the set up for the timeline will often be duplicated we only one of the facts (usually the one with the first date) in its individual timeline.