Why internet connection speed degrades for some sites using VPN?
There are several reasons on that. First, encryption takes some time. Second, connection speed depends on transit nodes between your network and a VPN server. These routes are not constant in time and can change even several times a day. Sometimes there is a speed loss on some transit node (“bottleneck”). VPN service stay fast, but connection speed may degrade for some users for these obvious reasons. Third, such “bottleneck” is also possible between VPN server and destination node (e.g. when you notice that some, but not all sites are loading slowly). We cannot prevent these issues as well as fix them. Finally, if you are located too far from a VPN server, you may encounter such problem when browsing your local sites. This is because the network traffic may travell around the Earth from a user to a VPN server and then back to destination host.