Sometimes, uploads or downloads to the StatsPlus servers are slow. This is rare, and the most common reason is some part of the connection between the user location and the server is dropping information (packets).
When this happens, most GMs in the league will have no issues, and some will complain that things are very slow or even unable to download altogether. This indicates the servers are running fine, but the route the packets are taking from specific users is problematic.
The easiest work-around is to try a VPN, which effectively causes the packets to take a different route and avoid the issue.
Most of the time, this issue is resolved in a couple of days at most. Trying other download methods as suggested at troubleshooting download issues can also help.
There is an application called MTR which can be used to gather information about the steps along the route from the user location to the server, and may provide clues as to where the issue is happening, which can be provided to the hosting service to try and resolve the issue.
There are directions to install and run MTR at Diagnosing Network Issues with MTR.
There is an alternate option for running MTR on Windows without installing an application at How to Perform a MTR in Windows, Mac OS, and Linux.
If you are having issues, and willing and able to run MTR, please share the output using the host of statsplus.net or atl-01.statsplus.net (depending on which server your league uses), and share the results with the S+ admin via DM or e-mail.