I just pushed a fix so that the old amber doesn’t display in the mythical island (in collection) and you should update the linked old amber card in the apex expansion instead.
After trying a couple of approaches, nothing really works perfectly. I decided eventually to just don’t display the linked card (the one in mythical island).
Note that the Overview page is listing the card in the progress counters and I use the amount owned from the linked A1 card so that that calculates correctly.