Hello, So I am having issues on my new iPhone 8 Plus with the stock mail app. I have a yahoo email account set up and sometimes it updates and downloads my emails and sometimes it doesn’t. It is not fetching any messages like I have it set up to do every 30 minutes. Even when I go into the mail app, it will not download any emails sometimes. It worked fine on my old iPhone 6...I’m not sure what the problem is? Thanks!