OpenVPN issues after successful connection

[oldfashioned]

Hello, I'm having an issue where my OpenVPN client has issues transferring data after I've connected. I'm able to connect successfully, and I can also ping the host I'm trying to connect to. However, as soon as I try and connect via https to load a web page the pings start to timeout. The web page will eventually load, but it's increadibly slow. Once the webpage has finally loaded, the pings will return to normal. At first I thought it was a packet fragmentation issue, however, I've added mssfix 1300 into the config and it's not fixed the issue. I'm using UDP. Any ideas on what the issue might be?