For those who have been unable to backup on Android, that issue is now fixed in the latest version 2.24.26013 on the Google Play Store. To make sure you get a full copy of your data onto your phone, follow the instructions on this thread to get the fix.
@Boris_Rybalkin What you’re describing with web being correct, but Android only showing transactions up to 1 Aug is addressed in the latest Android version (2.24.26013), which is different from the one you tried to reinstall 12 hours ago