Hi Kreichs,
Thanks for posting your question in Apple Support Communities. I see you've been having some issues downloading your original resolution photos to your iPhone.
Have you tried to Restart your iPhone and then try again? Download iCloud photos and videos
On your iPhone, iPad, or iPod touch with iOS 10.3 or later:
- Tap Settings > [your name] > iCloud > Photos.
- Select Download and Keep Originals."
Be sure to keep your device connected to both Wi-Fi and power as well to see if that helps. Feel free to reply back if the issue persists.
Take care.