Keep your photos safe (back them up)
A second copy helps if your phone breaks or gets lost. But a copy may not have finished yet. Online space can fill up. Sync means changes move between devices. That can include deletes. Keep a separate copy of photos you cannot replace.
Let us try with a photo you do not need. A blank wall is fine. Keep it on your phone until you can open the copy.
Let us go through this together, one little step at a time.
Tap each step once you have done it. Nothing is timed. Pause and check before sending, deleting, or agreeing to anything.
Free space has a limit. You can also copy photos to your own computer or drive. Open the copies to check them first.
The switch may be on, but the copy may not be done. Check the status. Look for space warnings. Keep a separate copy of photos you love.