Hello! I understand you're experiencing issues with Solitaire Grand Harvest getting stuck while attempting to retrieve cards on the rewards screen. Let’s troubleshoot this together.

1. Restart the Game: Sometimes, simply closing the app and reopening it can resolve minor glitches. Make sure to completely close out of the game before reopening it.

2. Check for Updates: Ensure that both your game and device software are up to date. Go to the Google Play Store, search for Solitaire Grand Harvest, and see if there's an "Update" option.

3. Clear Cache: Clearing the cache for the app can often resolve issues like these. Here’s how you can do that:
- Go to your device's Settings.
- Tap Apps or Application Manager.
- Find and select Solitaire Grand Harvest.
- Tap on Storage, then select Clear Cache.

4. Reboot Your Device: After clearing the cache, it might help to restart your device to refresh system processes.

5. Check Internet Connection: Ensure you have a stable internet connection, as the game may need to establish a link to retrieve the necessary data for rewards.

If these steps don’t resolve the issue, I may need to check further details to see if this is a common problem affecting other players right now. Would you like me to do that?