There are a few common reasons that your iPhone will say the memory is full when it actually shouldn’t be. One of those reasons is if iCloud logging isn’t running efficiently and starts to back up your iPhone’s memory. To correct this, tap on Settings and disable iCloud backup and then restart your iPhone. That should correct the problem and you can re-enable iCloud in order to keep your iPhone backed up about an hour or so later. At that point your iPhone should still be working better than before.

Another reason your iPhone will say the memory is full when it really isn’t is because of an app that is not running correctly. You may need to uninstall the most recent apps on your iPhone, restart it and see if the problem is corrected. It could also be that your iPhone has a virus. Installing a virus app and running it might help. If worse comes to worse, you may have to restore your iPhone, but that should be a last resort option.