Unfortunately, Samsung removed this feature with the release of One UI 3. We have no idea if we will ever get it back but I would suggest waiting till the next update as they might add it back. Hope this helped with your query 
Hi, just incase back up any pictures you might of taken with your camera then, long press on your camera application, in the top right press on the (i) in the circle, then scroll down to storage then at the bottom left then select clear data & hopefully after clearing, it should fix your issue, let me know either way.
