Bug: When opening MOM Packs in x10 groups, not all of the rares opened are shown
This bug is reproduceable by opening MOM packs in groups of 10. Exactly 10 rares are shown, but you are pretty much always going to get more than 10 rares from 10 MOM packs. I'm not sure but this might be the first time in MTGA when 10 packs can produce more than 10 rares, and nobody at Wizards thought to update the 10x pack opening UI. The issue definitely happens on the windows MTGA client, but I'd bet it happens on all platforms.
Additional data:
I opened 55 MOM packs on day 1. I did x10 open 5 times, and opened the remaining 5 packs together also. Of these 55 packs, the UI showed me in total: 31 MOM rares, 5 MOM mythic rares, 12 MUL rares, 4 MUL mythic rares, 1 rare wild, and 2 mythic rare wilds. Together this adds up to 55 cards. However, if I go into my decks > collection, and search for MOM owned rares and mythic rares, I have 55 cards. If I search for MUL owned rares and mythic rares, I have 18 cards. I have since bought 3 more MOM packs to test out and I see that opening 1 pack by itself does often grant more than 1 rare (Due to the MUL card potentially being rare), but the 10x pack open UI is not set up to display this yet.