Internet issues when using Netextender- Hardwired speeds go from 700/300 to 5/20...

Just in the last month, when I connect to work VPN through netextender, our 1GB internet comes to a crawl, will be around 700up/300dn with a ping of 15ms and then connect to netextender and it will be around 5up/20dn and ping around 200+.  

I have done a ton of research on forums, found some issues like this concerning wireless connections and the solution is to disable Receive Segment Coalescing on the wireless adapter, dont see anything mention for similar on a NIC.  

Anyone else had this issue before?  Using a brand new ATT router (just sent me a new one today 5268AC) running hardline to my desk with tp-link 1G switch. 

If I unplug NIC and just tether from Iphone, I can connect to Netextender and have 0 issues, speeds stay the same, so thinking maybe its a router or NIC issue?  NIC is Realtek PCIe 2.5GbE Family Controller.

Spent a few hours with our IT group yesterday, and they cannot figure anything out, just blame something on my end.  

Any help would be appreciated!!