If you are using network-manager-openvpn try to re import your conifgs for allrouted, netherlands, switzerland, and luxembourg.
If that does not work check my post for locking down debian based linux here
http://www.bolehvpn.net/forum/index.php/topic,6571.msg36718.html#msg36718There might be some stuff in there to try such as using actual ip's rather than server names. installing resolvconf etc..
What you might also want to do is grab the server names from the configs and ping them to determine if you are indeed having issues connecting to the servers or if it is a configuration issue. This will also help to determine which ones are faster for your location. Do this while not connected to vpn.
I had some issues connecting at first, note I am not located in the US. Also, I find the luxembourg and swiss servers to be really slow due to the way they route traffic. But all others nearly max out my bandwidth which is only 10.
I was told the reason speedtest says the servers are located in Kuala Lumpur is because that is the address listed in the servers registration.
Either way with Linux mint your are more than likely going to be having DNS Leaks, which might also be causing your issue with regards to your isp identifying a vpn connection and intervening (somewhat unlikely in the US).
Run this test here while connected under vpn and I bet you see your isp servers listed
https://www.dns-oarc.net/oarc/services/dnsentropy