VPN tunnel slow connection :(
 

Hi to all.
I have a dedicated server with Ubuntu installed on hardware (all updates installed)
WireGuard were installed.
VPN tunnel speed to Europe is VERY slow (Download 6Mbit/s, Uploading: 51Mbit/s)

Server's Speedtest :
https://i.gyazo.com/c94d371213d3a1e2...7d377743c6.png

There is CSF firewall on the server but i don't think the isssue is caused by this software.
Why the download speed of the VPN tunnel is so small? How to fix it?
Thank you very much.