If Gmail is not updating on your iPhone, then you are at the right place. Here we have some solutions to your Gmail not updating on iPhone problem. Let us resolve the issue by following the methods one by one.
Check if you have connected your device to the Internet. If you are using public Wi-Fi, determine which Wi-Fi you are connected to and make sure it has a strong internet signal.
Your sync customized settings will check the Gmail app for new mail every 1 to 30 days.
Gmail may not work on your device if IMAP is disabled in the settings. You will not be able to access your email account from the server if IMAP is turned off on Gmail.com.