>> I've built maybe 10 different Roon servers/cores, possibly more. Some Windows 10/11, some Ubuntu. <<
Understood. I've seen at least one post by a user who found many problems went away when they used ROCK on a Roon-approved NUC, instead of running under a general-purpose operating system. Obviously, there's no guarantee, and the only way to find out would be to try it, at some expense.