OPEN VPN very slow for client side

We have upgraded to 8.0 on our Peplink 305 and we are using Open VPN for a tech in Oregon and their Internet connect is roughly 100 Mb Down and 90 Mb Up…not a bad connection. When they log on to the VPN with either the route all traffic or split tunnel the speed goes way down when they do a speed test - like down to 8 Mb Down and 4 Mb Up. Now at the main office where the 305 is at we have three ISP connections and we have the remote site hitting our Cox Fiber connection witch is a solid 100 Mb Up and 100 Mb down.

We just can’t seem to figure out why the remote site is so much slower when then connect when we both have a very good internet connection.

Can someone lead us in the right direction here…like is there a way to throttle up the Open VPN connection…?