I'm getting a significant share drop on nanopool since upgrading to 1.6.4 from 1.6.2. Both machines doing the exact same thing

Everything appears normal within SRBMiner. Almost the exact hash numbers as 1.6.2. However, when I missed a payment, I went to investigate and I now realize my shares dropped by about 20-25%

https://www.dropbox.com/s/e76waamhah2dap1/hash%20drop.JPG?dl=0

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Windows 10, blockchain with a bunch of Vega64's