Hello, small updates for anyone that may run into same issues, yes, indeed apparently the motherboard needs a bit more time to recognize the new cpu, in fact in my case it took about 5 minutes of just running , then reboot with CMOS reset. This procedure I had to do about 2-3 times. Maybe I was too impatient and did not wait enough after first reboot with CMOS reset. But all of a sudden it worked and I managed to get into bios, set XMP and all, it seems fine now, just the cpu is running mighty hot (mid 90C) for a 4 core when under load in a Node 2020 with a Noctua NH-L9A. Will see if cannot bring those temps down, i might switch to an Alpenföhn BLACK RIDGE.
Thank you all again for your patience and advice.