Ryzen 3000 seems to have boot problems with the most modern Linux distributions. The problem affects all operating systems using a 2019 Linux distribution with Linux 5.0/5.1/5.2 kernels.
This problem is now known to be related to the RdRand command. Remember that the previous Ryzen processors were also not friendly when they used the RNG hardware command, which caused problems on the platform. However, now with Zen2, this is even worse supported, and AMD has not yet officially detected the problem.
The new AMD Ryzen 3000 have problems with some Linux distros
In early May of this year, AMD released an update for the system that helped solve the RdRand problems in the AMD Ryzen CPUs, but we still don’t see an update for this new problem and therefore it would explain why these new CPUs are not friendly and can’t boot a Linux 5.0 based distribution like Arch Linux or Clear Linux.
There seems to be an alternative solution to systemd, but the final solution should come with a new firmware or microcode that will allow any modern Linux distribution to boot correctly, as AMD did at least a few months ago.