Ive been having some intermittent connectivity issues for a few months now that present themselves as Connection Refused in the browser

They appear as below on my laptop, same error message on all phones or computers on the network.

Other devices on the network such as Smart TV's preset as "connection failed" or similar.

After around 30 seconds to a minute (sometimes slightly more) the connection just starts working again

I have my ONT 100 > Edgerouter lite > AP-AC Pro

Edgerouter is on firmware 2.0.9 hotfix 7 - I recently did a full factory reset of the device in trying to troubleshoot and is setup exactly as per the guide on this site. Edgerouter config: https://pastebin.com/P9qUaNhj

Traffic inside the network still functions perfectly fine, I can access the edgerouter config page and internal media server still functions perfectly fine the entire time.

I have also tried a different router that I was able to borrow from a workmate to rule out the router as the issue along with replacing all of the ethernet cables between the devices.

Doing more investigation, during a "blip" NSlookups show that I am getting an IP address result, I can also still ping successfully. Although this is hard to completely trust as sometimes by the time I notice a blip it comes back really quickly.

Any other troubleshooting type advice on what I should do, or is it time to try 2degrees for "support"