Unable to upgrade Ceedee Lamb to ICONIC with 5 Epic to trade

Hi, I feel like there is a bug that won't allow me to upgrade the current MM25 Ceedee Lamb to ICONIC when I have 5 Epic required to trade. I am using IOS. I've tried for a couple days once I collected the 5 Epic Ceedee Lamb cards, but when I go to trade, the trade screen only shows 4 available. In my collection screen, it shows 5.