Welcome here!
This "whirring" sound irritates me a bit, don't go for a ride until the culprit is found.
I would do as follows:
-change oil, fiil it up
-underseat tray out
-open CVT, start engine, locate noise
-cylinder head/ valves adjust at 0.10mm both
? does now what?
? same noise or less or somewhere else?
Pls come back for Qs!