google drive plugin not backing up on schedule

I have google drive plugin and have backups configured to be run daily. I have this set to keep the most recent 2 backups so as not to use up my G Suite disk space.

Currently All-in-One WP Migration > Google Drive Settings shows the following

Last backup date: July 31, 2017 5:59 pm
Next backup date: August 3, 2017 4:24 pm

Note yesterday it showed next backup as Aug 2, 4:24 pm

Is there a log to see why the backup is failing? I would have thought if there was some failure I would get an email at the specified email address, but I’m not.

Note the “last backup” on July 31 was done manually. Not sure if that confused things somehow. I considered deleting that one to see what happens, but wanted to check with you first.