Notifications from Gmail app?

Hi!
I use the Gmail app from Google but yesterday I didn't get a notification from the app.
What have I tried so far?
I tried deleting and reinstalling the app onto my iPad mini 2.
I tried sending myself a test email and I received the notification from the gmail app. However, I got an email from AppleVis a few minutes ago but I didn't receive the notification.
Has anyone else experienced this and how did you resolve this?
Thanks for your hebp!