It can be really confusing when your iPhone says your iCloud storage is full, even though it clearly shows you have space left. Since you mentioned you’re only using 25.7 GB out of 50 GB, but your iCloud Photos restore is paused, this is likely due to a syncing glitch or a delay in iCloud updating your actual storage status.
First, open Settings and tap your name at the top. Then go to iCloud > Manage Account Storage to check if anything unexpected is using space. Sometimes, other device backups or large app data can fill space without you noticing. Make sure your current device is the only one using a large portion of iCloud.
Next, go to Settings > Photos and look under iCloud Photos. If you see a message like "Restore Paused" or "Waiting to Upload," try turning off iCloud Photos temporarily. Wait for about 30 seconds, then turn it back on. This often refreshes the syncing process and helps your photos start restoring again.
After that, restart your iPhone. Press and hold the side button and either volume button until the slider appears, then turn off your phone. Wait a few seconds, then turn it back on. A simple restart can sometimes fix stuck sync issues.
Also, make sure your phone is plugged into power, connected to a good Wi-Fi network, and that Low Power Mode is turned off (you can find this in Settings > Battery). iCloud syncing works best when your phone is charging and not in battery-saving mode.
If none of this works, as a last resort, you can sign out of iCloud and sign back in. Go to Settings > [Your Name] > Sign Out at the bottom. You'll need your Apple ID password and will need to turn off “Find My iPhone” to complete this. After signing out, restart your phone, sign back in, and turn on iCloud Photos again. Only do this if you’re sure your photos are already backed up to iCloud, which you can confirm by logging into iCloud.com and checking the Photos section.
In short, your iPhone is likely having trouble recognizing the available iCloud space, but it’s usually something that can be fixed with a few simple steps.