Not sure if this finding is new, but the author from FASM Thread apparently has a Zen 2 (He doesn't directly mention anything besides "Ryzen 7", some other poster mentions it is a 4800HS). There were a number of articles about RDRAND being broken on Zen 2 and earlier generations but fixed via Microcode from about 6 years ago:
zir_blazer · · focus · HN ↗
<a href="https://www.phoronix.com/news/AMD-Releases-Linux-Zen2-Fix" rel="nofollow">https://www.phoronix.com/news/AMD-Releases-Linux-Zen2-Fix
<a href="https://arstechnica.com/gadgets/2019/10/how-a-months-old-amd-microcode-bug-destroyed-my-weekend/" rel="nofollow">https://arstechnica.com/gadgets/2019/10/how-a-months-old-amd...
No idea what happened after. And that also means that you suddently need information about user systems BIOS/Microcode.
rurban · · focus · HN ↗
<a href="https://rurban.github.io/dieharder/QUALITY.html" rel="nofollow">https://rurban.github.io/dieharder/QUALITY.html