Using an old version of the .obb (even though google says it is exactly the same) never works in corona), it is most likely a corona issue but it has never been resolved or looked at I assume.
To be safe you have no choice but to ALWAYS use the latest .obb with the latest .apk otherwise you will get the issue you are mentioning with corona not being able to find the .obb because it is most likely looking for the new .obb name…