1. I use both operations: getNetworkClientsUsageHistories and getNetworkClientsApplicationUsage.
2. getNetworkClientsUsageHistories also has the same problem with the same Cisco clients.
It happened when I used timespan=1000 and when I used timespan=7200.
In the case I opened, I put all the needed information (net ID, client IDs), but I got strange responses from the support team.
As far as I understand, there is a bug in those 2 endpoints. There are 2 options to fix it:
1. Remove the problematic devices from the client list of getNetworkClients.
2. Or ignore the problematic clients when responding to getNetworkClientsUsageHistories or getNetworkClientsApplicationUsage.
If the Meraki R&D team has a better solution - welcome!
p.s. I found a real bug. Why does no one give me kudos?