So I did some research on the issue, it appears that its related to how Google Play Store uploads their stuff. So the first time you upload your .APK it doesn’t let you upload the OBB file with it.
The second time you upload the .APK file it lets you attach an OBB file but it won’t let anyone download it to their phones. If you copy it over manually to the phone into the correct directory it works.
I haven’t tried this yet but I’m guessing its the solution to this issue.
The Third time you update your .APK file it lets you attach an OBB file and it actually lets people download it. (This is my guess I haven’t actually tried it yet).