Added Item doesn’t Save

My app has been running slower recently & I’ll add a new item and it won’t save and show on a new line. I have to change to another list or close the app and then re-open for the item to appear. Sometimes it doesn’t appear at all. 

The last time this happened I deleted the app and re-added and logged in to sync. Now all of my lists are back but items within lists are missing. Still showing 0. Help!