If you're using a Newsify account, try restarting your device first.
If that doesn't help, you can try creating a new Newsify account using the Account setting (you'll need to do this if you deleted Newsify's iCloud data using the device settings). In the app settings, select Account at the top (you'll have to wait a couple of minutes until you get the Sync Failed popup or this will be disabled). Then select Add Account... and then Newsify account type.
Also, if Newsify completes syncing but changes to read items or subscriptions aren't reflected, you can also try turning iCloud Drive or iCloud Documents & Data off and back on again in the device settings under iCloud.
Make sure that Newsify is enabled in the device settings under General>Background App Refresh and Notifications and that the Background Sync Interval is set correctly in the app settings under Sync Settings.
Make sure Low Power Mode is disabled under Battery in the device settings.
Also, if you've just started using Newsify or have re-installed the app, you may need to use the app for a week or more for background sync and notifications to start.
In addition, you'll want to avoid forcing the app to quit using the iOS app switcher.
If you still have problems, you'll also want to try restarting your device.
You can reduce the amount of battery that Newsify uses by doing the following:
1) Disable Newsify in the device settings under Background App Refresh. Also, change the Background Sync Interval setting to Off in the app settings.
2) Under Sync Settings, disable the Unread Items and Starred Items settings under Download Images for Offline Use
3) Under Sync Settings, disable the Enhance Feeds setting (Newsify accounts only)
4) Under Sync Settings, reduce the Max Sync Items setting
5) Change the Show Thumbnails setting to Off
You can get a list of individual subscriptions within a folder by tapping and holding the folder or by tapping the gray circle icon to the right of the folder name and unread count. To edit, you can then tap the edit button in the upper right.
You can also change the Open Folders As setting to Subscription List. This will cause the subscription list to be opened by default when selecting a folder.
You can clear the cache by selecting Clear Image Cache under Sync Settings in the app settings. You may also want to consider adjusting the following settings to reduce the amount of storage space needed:
To disable pre-downloading images for offline reading, change the Unread Items and Starred Items settings to off under Sync Settings->Download Images in the app settings. Images will still displayed when online but will not be downloaded before they are needed.
You may also consider reducing the Max Sync Items and Keep Read Items settings under Sync Settings as well. This will reduce the overall storage space required by reducing the number of articles and images that are kept on your device.