No restore or purchase possible- extreme Bug!!!

### Platform

- [x] iOS
- [ ] macOS
- [ ] tvOS

### In-app purchase type

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

### Environment

- [x] Sandbox
- [ ] Production

### Version
0.13.3

### Related issues

## Report

### Issue summary
If the user quits the app while non-consumable items are either restored or downloaded or purchased, there will be no possibility of purchasing or restoring items when reopening the app. The only thing helping is pressing the home button and on/off button for a soft reset. After this, it will work again... So what am I doing wrong or how can I solve this? I have included the finish transaction in my app delegate btw...

### What did you expect to happen
Restore / purchase possible

### What happened instead
Nothing... Pressing the buttons was without any effect...