I don't know what's going on with the store but I can recommend obtainium. You can add the amethyst repo there and update directly.
Hey nostr:npub1gcxzte5zlkncx26j68ez60fzkvtkm9e0vrwdcvsjakxf9mu9qewqlfnj5z just to let you know my gf's Pixel 6a running GrapheneOS can't get Amethyst from the Play Store. I have no problem with it on my Pixel 6 Pro also on GrapheneOS.
Can't find it on IzzyOnDroid repo anymore either.
I did install it direct from GitHub but would be good to get auto updates, also not sure how many other users/devices this could be potentially affecting.
Just letting you know mate, appreciate all the great work you do 👌
