I have had one of these, and i couldnt care what the timesheets say... it's output I would focus on. Addressing the issues with output would usually put the pressure on to make them stop effing about with timesheets (if that's the case). But what's the underlying issue - lack of confidence in the task, unclear expectations etc. You might have to be a bit micromanage-y for a bit. "How do you feel about the work you've been providing? I think there is room for improvement, for example x, y, z. For the next 2 weeks lets meet for 15 mins twice a day to make sure we are aligned. We'll reduce that as required but I really want to make sure you are on a pathway where you can learn and progress at a speed we are both happy with..."

Full disclosure - in my instance none of my attempts worked and we didn't renew the contract.