Well, this is interesting
I have tested a lot of AMD GPUs and never saw the "GPU Power" being reported. This value is actually retrieved via AMD's 'official' interface, while "GPU Core Power" and "GPU Memory Power" are read using a different proprietary method. Unfortunately AMD doesn't provide more information about the meaning of those values, but since the "GPU Power" value is read using an 'official' method and because that value seems much more reasonable than the other two on your GPU, I'd trust the "GPU Power" value.
It's also possible that the "GPU Core Power" and "GPU Memory Power" might require some adjusting for your GPU.
Can you please provide the HWiNFO Debug File of your machine? Also it would be helpful if you could provide values of all GPU parameters while they are stable (i.e. stabilized when GPU is idle, or under a constant load). I'll then have a look if it's possible to fix that.