Walmart Cards Online?

In previous months I have earned several Walmart gift cards and added them to their website and combined them either into a plastic card or emailed into one large gift card. I haven't used it for at least a month, but now when I go into the Walmart checkout, it wont let me use gift cards for either option anymore. What is up with this? Just something for the holidays? Will I have to start taking them into the store to combine them now?