I see so many same issue on this topic and it seems there is really no solution as I have tried every single possible things recommended and suggested in the internet..! I think this is a design flaw either software/maybe also hardware by Apple on this models. Apple really should give their position and fix on this..!

Hi, I am also am having the same issues and had to disconnect the second monitor. I tried all sort of combination to see if the kernel_task reduces the load but no luck. only when I disconnect the second monitor it seems it goes back to normal. I haven't tried to clean and re paste the CPU and the fans but when I look at the fans it is very clean. not sure if this really an issue. I also run the Macs fan control app to control the fan speed and the temp but I think this is not related to the issue. I also tried the SMC reset and NVRAM etc., but last only few minutes and its back again.... I am very frustrated.. I am running Montery on my mid 2015 MBP... any help really would be appreciated. thanks