After the New Roon Update: with upsampling the processing speed decreased strongly

Definitely relevant in this case. When you have read only 74 posts, you really do not know that much about Roon, especially the vast body of information that has been posted about Roon here over the years.

Well, good luck with that assertion. Because clock speed intensive sample rate conversion clearly is not working well with the 24 core, 32 thread processor in question.

AJ