Use “Tell a Story” (+2/+2), and “Tall Tales” (+4/+4, +2Mana). Neither applied on the copies.
I also stuck a “Han-Cho” (+5/+5) and a triple “Grimestreet Outfitter” (+1/+1 x 3) hand-buff and using “Overpowered” treasure (double cards played), then two copies of “Bran Bronzebeard” (double Battlecries). These did apply.
This has to be a bug. the card says summon copies of the card. These buffs are not in-match buffs, so likely the code is different and isn’t registering to this older, rather unique card.