If you have a full six card hand then Nissa’s Expedition won’t cast. If you place it as the first card in a full hand it gets skipped and your other cards with full mana are cast until you get down to 5 cards and then it goes back to cast the Nissa’s Expedition. If you have 5 or less cards in hand then it works as expected.
Hello @Xibvert ,
Thank you for all the information provided, this issue will be investigated!
If you have any additional information that you consider relevant, please don’t hesitate to send me 
Rebeca.