This has been a problem for a few expansions now, but it has been getting worse with every expansion as more slots are added to the UI and is especially bad with people who pay for the Merchant's Perk. This is an issue for Custom UIs that feature a BigBank window that displays the bags open so the slots are visible all at once like the bank window featured here: Bags Open Bank or in the AYA UI. If you then try to open all your bags in your inventory at once, even if you don't have the bank window actually open, it only displays some of the slots. Currently on beta it opens the first 6 bags but the slots for the last 6 don't appear at all. It looks like this: I understand this is a limited issue for specific custom UI users and I'll likely get responses from players like "just use default" but there are a good number of us that still really enjoy the game using our custom UIs that have features added to the game long ago to tinker with and make the game look the way we prefer it and it would be really nice for us to be able to use these features we've grown accustomed to and still be able to open all our bags at once. I remember there being a bug post about this a few years ago but when I went to bump that one it seems to be gone so starting a fresh one. Thank you for your consideration on this issue!