We've seen similar behavior due to some limitations in Cisco's WAAS related to SMB. I eblieve the latest versions support SMB3 better, but we had to bypass some of the acceleration due to this and some older hardware at sites we haven't refreshed yet. Here's some Cisco release notes that discuss the newer functionality:
And here's some screenshots one of my network admin shared of our config speficially related to this issue:
Hope that helps!