I've been pondering about moving your question over to this topic, since the last couple of post contain the same issues. Take a look over there, perhaps there's a solution.
I don't think there's a change in rate limiting, and 1 per minute is definitely not too much. If you'd really like someone to check the logs, perhaps @dave could help you out.
I know Google can be sensitive about how their apps hit other servers. When your core is offline and they make a request, they can receive a timed out status code, which their servers interpret as a “whoa, slow down” signal.
A while back some people from Google reached out to us and tweaked some controls internally on their end, so it’s possible something reverted there?
I’m getting soooo many fetches failing it would mean my core is offline A LOT. Meanwhile other internet things in my house work fine. But, maybe it is going offline and if you see that in your logs, that’s valuable info:
Spark id: 53ff78066667574857420967
Also, I work at Google so I’m asking some people I know wazup