Internally, the jlab deck always is called “Jlab’s beginner course” – even though there’s a typo in the name ;). If you rename the deck to e.g. “wafawffwa”, you will get a second deck with the original name after import. The “old” cards are now in “wafawffwa”, the new cards are in “Jlab’s beginner course”. In order to fix this, you need to move the cards around in the deck browser (from “wafawffwa” to “Jlab’s beginner course” or the other way round). Afterwards, you need to update the card order, as illustrated “wrong card order (fix 2)”!