Hi,
According to your description, my understanding is that the BranchCache performance monitor on test PC and hosted server DataCache size are not been changed when copy file from SharePoint library to the test PC.
BranchCache for use with SharePoint Server 2013. Reference link below to verify that you have the following memberships:
https://technet.microsoft.com/EN-US/library/jj721440.aspx
Besides, disable related firewall temporarily and check below options:
1. Ensure that BranchCache is enabled and that both clients are configured to use the same caching mode using the
netsh branchcache show status command.
2. Verify basic connectivity from both client computers to the Hosted Cache using the
ping command.
3. Ensure that the certificate is properly installed and bound to port 443 on the Hosted Cache computer.
Best Regards,
Eve Wang
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