In the example you posted it looks like you are using the V0 API which I think is now deprecated, do you see the same with V1?
Fwiw I use the API across several organizations for monitoring/stats/analytics, using quite a few different endpoints, currently with the Python V1 library. Defensive programming with plenty of error recovery is essential, the error recovery in the library is certainly not always enough.
There will be faults at times, some may take quite a while to fix, but there will also be transient faults, including Internet/other issues unrelated to Meraki's infrastructure, all can disrupt things.
One thing that may reduce issues is using an organization's specific shard rather than the generic api.meraki.com, there's another recent thread about this.
You mention polling every minute, if that is on multiple networks/devices in an organization you might also be hitting the rate limit at times.
I guess you prefer the same approach on multiple vendors, but it seems odd to do such frequent polling of an orchestrator that can itself send you alerts as/when they occur, maybe you could get what you need more reliably via webhooks?