Hey there,
@KimberH
There isn't anything in cPanel that limits the upload or download speed from the server. That would all be up to the speed of the server's network connection, and your ISPs connection to the system.
You may want to try performing a traceroute test from your local workstation to the server to see if that shows any slowness on the network. The traceroute section is about halfway down this article:
Here are some basic server-level tools that system and network administrators can use to troubleshoot network issues. These tools either come with the server's operating system, or you can install ...
support.cpanel.net
If you see a sudden major increase in the time it takes to make the connection, that could indicate slowness on the network between you and your server. if you don't see anything odd there, it would be good to get more details from the host about the speed issues and have them check that on their end.