I am having the exact same issue, recently upgraded from 16x to 17 (Build 6928 ) , averages around 5-10% CPU, then what seems randomly will instantly jump to 70, 80, or 100 CPU until we restart the service (not a spike, it is continuous until restart).
I tried stopping the indexing service and this did not change anything for me, maybe it only affects it after a service restart/reboot?
Twin Vision Studios, Inc.