So, more conclusive data.
The only think I can do to prevent system hangs is to disable Global C-state Control in the BIOS. With that off, the system is stable with no hangs in nearly two weeks. It therefore appears that this is indeed the Linux-AMD bug referred to in an earlier post.
As to why it occurs more frequently with Roon running, I don’t know. I have not tested for a longer period of time with another player, but suspect that eventually a hang would occur.
I am also uncertain if the current generation of AMD processors are affected, but I am not going to take the risk to find out.