I have tried to drag the new version into the Sideload tool, but it doesn't recognize it as a new version. Is there possibly some metadata that needs to be updated?
FWIW there was a version without the metadata, and then another new version (1.1) fixed that—and for me, this latest version did update just fine via web sideload.
Can you try again with the latest upload? I have just incremented the build number and changed another setting in the metadata. I hope you'll be able to update the game.
