2024 Hyundai Kona Electric High Pitched Noise after shut down

It sounds like a switch-mode power conversion system operating outside of its normal parameters. The LDC and OBC/V2L are such systems. Wondering if it's the V2L winding down? Plug something into the cabin outlet before switching off the car, preferably a resistive load like a hair dryer.

I would want this to be addressed promptly by the dealer.

 

You've said sound is coming from trunk, but video is of hood/bonnet/engine area.

Sounds like the pitch is slightly dropping. My bet its something to do with pressure/liquids/gasses being let through a valve as part of post-operation cooldown. Or worse, escaping from somewhere it shouldn't.

Simple check like the cap on the coolant reservoir tank. Is it screwed on well/correctly? How about the hoses/fittings going into and out of this tank. Does giving them a wiggle and ensuring they are fitted correctly and not leaking make any difference?

Another idea: when driving the car today, don't use the AC. Then when you get home see if it still happens. If you had used the AC during your trip you may be able to assume the AC compressor has been running and there is a good amount of pressure in the high pressure system. If you haven't used the AC and the noise doesn't occur, then perhaps it may be related to the AC system whenever it is used/pressurised?

Are you absolutely sure it is not coming from the grille mounted speaker? A long shot I know.

How new are we talking? 100 km's since new? 1,000? Just thinking if it is absolutely hella new and you've only done 100 km then maybe coolant still hasn't found its way everywhere around the system and there's a small pocket of air trapped somewhere on a certain side of a valve which opens/shuts depending on temperatures in certain systems. Perhaps after a few proper heat cycles it will rectify.

How about popping off the plastic dress-up cover on top of the motor and the next time it happens give some of the coolant pipes in certain locations around the motor/inverter/radiator etc a bit of a squeeze and see if it changes the pitch of the noise. There is a pump and also a valve assembly/device in front of the motor which turns on and off at certain times for running the coolant through the system and also running the coolant through different devices (or not) within the system. If squeezing the pipes around these areas has an effect on the noise maybe you have helped pinpoint the problem and it will be a cooling pump or valve in the cooling system needing to be replaced.