Same here ☹️
I found out the reason why. Apparently Shirokoi says sometimes the APK doesn't work properly if there's a previous version installed on the phone, but, after looking at other comments, there IS a workaround. What you need to do is find the saves folder in your phones files and make a copy of it somewhere, then uninstall the old version. Install the new version after that, then move the saves into the appropriate area. This worked for me and I was able to play the update fine.