Skype for Business network connection issues

I've recently changed to a new ISP as due to living remotely I can’t get traditional fibre, so I’ve switched to the satellite hybrid provider. They provided me with a cnPilot r200P router (which they don’t like me to access!)  which seemed to install easily and generally I'm not getting between 6 and 7 Mbps down and 5Mbps up, which is a vast improvement on previous BT speeds. However since installing, I have been having sever issues using VOIP - more specifically Skype for Business. It works one minute and then just drops connection and gives me all the various network connectivity issues - although if I ping my network it looks ok. Often I make a call out, which connected and I can speak for 4 seconds then it dies and I can't hear the other person but they can't hear me - if they call me back then it works ok. Other times it won’t connect anything at all  -not even to the skype test call, yet the network looks to be pinging back 7Mbps. I’ve had the ISP out twice now, they have also updated the firmware but I'm still getting the issues. Its not my laptop or software (his has all been checked, repaired and I have a brand new laptop), this issue only happens on my home network. As it seems the ISP is running out of ideas I'm wondering if its a route config issue?? Any ideas welcome!!

We didn’t face any such issue with Skype for Business with latest 4.4 firmware and please ask the service provider to update the firmware of r200 device.

Have you observed the behavior when the PC is connected to your WIFI networks?

if Yes, Please provide your observation if PC is connected  to Ethernet LAN port of R200 device