This is an Android Oreo specific problem and is being experienced by a lot of users who have updated their Pixel and Pixel XL smartphones to Android 8.0.0 OS.
Currently, the only way around this Android Oreo bug is to open your account via a web browser or via PC.
Nearly all recent reviews for the app on the Google Play Store complain about this, as you can see from the images above, and user frustration is plain to see.
I mean, if you're receiving emails, it's kind of important to be informed about them, right?Setting/data usage/google services I have never touched this option before so I don't know why it was checked.After these two steps my phone works perfectly now.A new bug which we have come across causes trouble when it comes to syncing e-mails.A number of users have reported this issue in the Pixel Users Community on Google’s product forums.I've searched on Google Help but couldn't find anything.I guess I could use the Email app but I don't like that as much as the Gmail app. Just found this thread and it helped me solve the same issue (gmail not syncing on mobile data) on my Galaxy S3.Now, your emails should start syncing over both - wi-fi and Mobile Data too. Made sure that the Data restriction is OFF for your specific app or is OFF in general. Your Data is switched ON and has correct APN configured. Your Background Data usage is set to enable for the specific apps. Because it has attracted low-quality or spam answers that had to be removed, posting an answer now requires 10 reputation on this site (the association bonus does not count).Would you like to answer one of these unanswered questions instead?But finally with this site I come up with the APN reset solution.I did it and also I have found that google services had the check mark ON for restrict background data.