Inconsistent purchase and restore purchases results on iOS 10/11

### Platform

- [X ] iOS
- [ ] macOS
- [ ] tvOS

### In app purchase type

- [ ] Consumable
- [X ] Non-consumable
- [ ] Auto-Renewable Subscription
- [ ] Non-Renewing Subscription

### Environment

- [ ] Sandbox
- [ X] Production

### Version
0.10.5

## Report

### Issue summary
In production I am currently having some inconsistent issues.

When a user purchases the IAP in my app the purchases is successful and they get the successful purchase UIAlert. However, the effects of the purchase do not take place. I informed the user to use 'Restore purchases' to make sure that the effects of the purchase happen. However, when the user selects 'Restore Purchases' they receive nothing back, along with my UIAlert that tells them that there is nothing to restore.

This issue only seems to be occurring on iOS 10 devices. I have tried to replicate the issue on iOS 11 test and live devices but I cannot replicate it.

I tried to replicate the issue on an iOS 10 device twice and had one result where the IAP was successful an another where it failed.

Has anyone else come across an issue like this?

Any help would be greatly appreciated.