This may or may not be helpful.
I have a couple of large networks (Hub and Spoke) wih constant but light API traffic for a legacy app that doesnt support encryption)
eg 100 Spokes connected to a single Hub Client.
I had auto update disbaled on the Hub intentionally so i could manully perfom updates.
We were seeing HIGH CPU usage for the last 24hrs.
With no where else to look troubleshooting i updated the Hub verson
The last 3 digits of the version change were 406 > 410
CPU usage resolved.
If this is your issue i would start by updating any Hubs manaully in your networks that are causing issues>
Help Menu? > Update verson (or similar)