Board Game Arena

At the end of a round, in my opinion, everyone gets 8 traveling-cards.
The rules tell that everyone has 8 to 12 cards in the next round.
I had 4 cards left from the first round, so I should have 12 cards, but the online game fills up till 8.
Does anyone know why?

I looked up my (dutch) rules and to my surprise it also says that you can keep max 4 cards from the previous round above the 8 new cards you get.

Seems there are/were 2 versions of the rules but the one here on BGA seems the newer or most prefered one.
See the following thread from BoardGameGeek:
http://boardgamegeek.com/thread/381364/hand-management