Thank you very much for the many suggestions.
Indeed I went back as many of you suggested, to look at the cooling fans inside the case. Found one fan not turning at all and the second was factory installed in reverse, blowing in instead of out.
Now cpu and gpu are running in idle at 35C and 45C. Which is very nice. While running MSFS in Ultra at 81C and 82C respectively.
Still hotter then I wish but more reasonable. I think my i9-10920x is just a hot unit.
Thanks again