Hey all,
We are still investigating this on our end. In the meantime I do see a number of players reporting that installing through Amazon App Store works to bypass the issue. Keep in mind that this is only a work around while we investigate the problem. If you’d prefer to wait for a fix, you can keep an eye on this thread for updates.
Game Progress in Hearthstone is tied to your Blizzard login, so it should be safe to uninstall / reinstall through the Amazon store if it is available to you. If you want to go back to the Google Play version after that version is fixed, you will need to uninstall the Amazon version and go reinstall the Google Play version.