Outlook app doesn't synchronize when in background
I have an iPhone 8+ with iOS 12.4 and the Outlook app. I think this used to work but doesn't anymore: when the app is in background (when phone screen is locked/off, or even when using the phone but other app is in foreground) it doesn't sync email. Not until I bring it to the foreground, when it automatically syncs right away. Apple's Mail program does sync on its own, in background. Any way to make Outlook sync every so often, even if it's not in foreground?
iPhone 8 Plus