Best is to read through the API documentation, there are several endpoints for this sort of info, I use getNetworkWirelessDevicesConnectionStats to get network wide details, and use that to determine the different failure types to present in summary form.
In the instance you mention of a network-wide issue, that is something you would need to detect and manage - one AP showing issue == it's the AP, all APs showing the issue == it's the network/other necessary service like DNS, RADIUS etc.
If you use the Meraki Python library async I/O calls, you can speed things up a lot, even with hundreds of sites and thousands of APs you can gather the data pretty fast using the call I mentioned.