B650 Steel Legend WiFi no POST suddenly

Try doing this:
https://forum.asrock.com/forum_posts.asp?TID=630&title=how-to-clear-cmos-via-battery-removal

Make sure to leave the system fully disconnected from power for about an hour.
Sometimes a failed sleep state can cause the system to fail to POST, typically
following the linked steps will resolve the issue if it is not a dead/dying CPU.

If this fails then I would have a local shop look at it for you, it may save you
time, effort and money if they can at least determine what the fault is caused by.

Good luck.

I would initiate an RMA on the CPU too, that way they will test it and return it
if it's fine or replace it if not. With issues like this it's typically best to
RMA all the suspect components.

Good luck and let us know how it goes when you get the replacements

No one knows for sure and none of the manufacturers are talking. Personally, that
makes me suspect AMD. If all the other brands were wagging fingers at ASRock or
another brand that would be different but they are keeping quiet too.

Blame aside, ASRock did release this statement a few days back, along with BIOS
updates intended to address concerns:
https://www.asrock.com.tw/news/index.asp?iD=5744

In spite of all the publicity and attention being drawn to this issue it is still
an exceedingly rare occurrence. To put it in perspective, there were more dead
CPUs caused by intel's mess up with 13th and 14th gen microcode. These things
happen. It's better for it to be a known issue that is receiving support and RMAs
than for it to be completely isolated and potentially fall outside warranty etc.

As to sticking with the platform, that is entirely up to you. Personally, I
would see how it goes with the replacements and the new BIOS updates. If something
goes sideways again then swap out the 9000 series with a 7000 series CPU and be
done with it. As in, get the replacement CPU (RMA) then sell it and pick up a
7000 series equivalent. In all likelihood your system will be fine now. It would
seem AMD has been working with all it's board partners to get the the bottom of
this issue.

Bare in mind, all AM5 boards available gave no issue with 7000 series CPUs.

As for this being an ASRock issue, no, it isn't limited to ASRock, other manufacturers
are experiencing failures too, it wouldn't surprise me if they all were. The
reason ASRock has gotten more attention is because more users reported burned
CPUs on an easily accessible redit group. Reports of similar issues from other
brands were not so neatly collected in one place. I believe there have been more
reports of failed CPUs on ASRock boards, I am not trying to say otherwise, but
not by anywhere near the margins the media is trying to claim.

To put your mind at ease, even if you run into problems again, they will be addressed
again. I doubt that will be the case however, you should be fine with the new
updates.

Just sit back, enjoy your build and keep an eye on the ASRock news page for updates
etc.