For the Gmail Not Working issue, you can start applying the following technique. On your mobile device, you can force Gmail to close and then reopen it. These steps can be used to do the task on iPhones. Launch the iOS App Switcher first. Next, swipe your screen up to the center. Additionally, locate Gmail and swipe up on the preview. It will also forcefully close it. Finally, return to the home screen of your device to reopen it.