What causes the Delta % of an order to go into the red. I understand Delta is the difference in measured hashrate between the pool and nicehash, I'm just not sure what causes it? I had a fixed order that was at -100% Delta for a few mins so I was paying for hashrate that wasn't being counted by the pool, it seems strange the nicehash servers can tell the pool isn't getting the hashrate yet it continues to charge for that hashrate.  I deleted the worker at the pool and created a new one with the same name which seemed to work, I just want to know what causes a negative delta % and is there anything that can be done on my end to prevent it, also why does the nicehash system allow a -100% delta rental to keep paying for hashrate they aren't showing at the pool?
Thanks
Best Regards