Owners manual... Near as I can tell, VW does not have an on line download of the owners manual so I can't use this source to figger our the light issue you described.
I did find the below forum threed discussing daytime running light stuff for some recent year Jettas. Weird light stuff! This forum could be something for you to join up for asking some VW enthusiasts on this or other questions or discoveries you have over time.
Thanks for the link.