Final Fantasy VIII - Card Collector achievement (Steam)

I recently made the effort of collecting all the cards in the game. No biggie, I love the card game anyway.

Got the PuPu card last.

I now have the yellow start next to the "Cards" menu entry, and the entire list is filled, however, I'm not getting the Steam achievement "Card Collector" which requires you to get all the cards.

Now, obviously, I've Card Modded a lot of cards into powerful items, so some of the entries in the Cards menu have a 0 next to them, signifying that I have had them, but no longer do.

Question:

Please tell me this is a bug, and that I don't need to own every card simultaneously to get the achievement?

And also, how hard is it to re-gain all the cards on Ragnarok during Time Compression (Disc IV)? I can play the CC Diamond, who seems to have all the level 8, 9 and 10 cards I need, but it's hard to find the level 1-5 cards I no longer have. They seem to play only in the 4-10 range.

Any help appreciated!

For the record, it's my favorite in the FF series, so I've already started another playthrough with the intent of getting the achievement if it turns out that I do need all the cards at the same time, AND it's tricky to get the low-level cards on Ragnarok.