Issue trading in ICONIC Barkley and Bowers for mythic

I obtained my first iconic Barkley and Bowers during preseason and got my second Barkley last night for getting lvl 50 on field pass and got my second Bowers today from obtaining level 40 offense reward. There seems to be a difference in two stat categories for both (with an increase for all stats for new barkley and +4 physical and +6 reciving for bowers). It will only let me add in the ones from preseason with lower stats. When I remove the original ones I got during preseason and replace with another random uncommon player it shows the iconics as a 2x for both but then when i go to the trades to get the mythic it only shows one. I dont know if this is a bug or if it is due to difference in stats of cards.