I have the same issue, the costs in time & effort to "upgrade" from Quickbooks Desktop 2014 to Quickbooks Online was bad enough, not counting the $100 a month I pay Intuit. 

I often get a prepayment from a client and bill against the amount the customer prepaid. My invoice shows PAID and a TOTAL DUE of $0.00, but no where does it actually show what the total of the invoice was. I thought it was my mistake, but I can see no way to go into the Invoice Format and add that. 

Whoever wrote this software has never ran a business, invoiced, punched a clock, or handled any business activities. 

The answer from Quickbooks is always to clear my cache, use a different browser, or log out and reboot. 

My customers must think my business is a joke.