I’ve seen meny have similar problems, but nothing really seems to fit my use case so lets have a go:

Ever since I started to use GA on my Arc I intermittently get the famous “I can't reach the internet right now ...” message. 

First I thought it was that I was running the speaker on wifi and there was interference from the neighbours, so I switched to wired directly to a port on the router.

Problems persisted.

Next I thought that my pi-hold blocker was doing something, I checked the logs, found a few blocked requests and whitelisted them.

No more red in the pi-hole log, problems persisted.

Next I made notes on circumstances, like if I had been using the TV, or streamed from a computer or Spotify, before it stopped working or if it worked during, which app as in from which device had accessed it last and so forth.

Sometimes it worked, sometimes not in all cases.

Next to check was if the message coincided with specific times of day or day of week. 

Same again, sometimes it worked, sometimes it didn’t. Time or day didn’t matter. I could have it working for a while, then it wouldn’t. That stretch could last for minutes or hours or till the next day, then it worked again like nothing had happened. 

In all this, router and arc have been restarted several times for updates or just because. 

So I’m out of ideas on what to try next.