OpenDNS causing internet outages

Here is my issue. I have had my R7000 for about a year. Over the last few weeks the internet connection has been VERY patchy. One moment fine, the next NOT. Sometimes one session (such as streaming video in a browser is working) whilst the next browser session can't connect. The Web interface to the router sometimes reports the internet is down even whilst I am streaming data!

I found the cause and it's OpenDNS. I would really appreciate some help as I want to keep the level of protection for my kids that OpenDNS goves but at the moment it is causing terrible connectivity issues.

Symptoms

If I switch off parental controls via the netgenie app on my PC and enter the ISP primary and secondary DNS settings everything works fine. The minute I switch on parental controls the DNS settings on the router goes back to the OpenDNS settings 208.67.222.222 & 208.67.220.220 and the poor problems return.

This thread (which is now closed) https://community.netgear.com/t5/Nighthawk-WiFi-Routers/R7000-router-drops-internet-connection-frequently-after-enabled/m-p/1034489#M25051 is the closest to my problem. It appears they did not communicate for a while so it is shutdown but I think they are having my issue.