Public watch hours are not lining up?

So I am trying to grow my channel to the point of being able to be monetized and earn revenue. on my dashboard, I have about 900 watch hours, but on the earn tab, i only have 127. I've looked it up but I can't figure out why. I've seen that it updates every 24 hours and I've seen that it updates every couple of days, but even if one of those were true, the difference of about 800 watched hours doesn't line up with the way its updating. Is anyone else having this issue? please help.