Tracing a thermal throttling problem

My legion 5 15arh05h is running incredibly slow, hwinfo shows the processor clock locked to 399MHz due to PROCHOT_EXT, which seems to indicate some other component on the board is signalling that its too hot. Problem is this is happening even from cold boot and none of the sensors available in hwinfo are showing any abnormal temps so it seems like a sensor faulty but there is no more info given on what sensor is calling for the throttling.

Is there any way to trace/diagnose this further?

Thanks.