Roon Core shutting down after a few days running 24/7

Yes you are. The forum’s #support category is exactly that. Support may ask you to fill out the other questions in the posting template, so it will speed up things if you do that.

There is a known issue with a - for some - frequent crash on macOS. This shows with “Crashed Thread: .NET ThreadPool Worker” in the Mac’s crash message, if you get one. Roon are working on a fix for that one and a workaround is available in the meantime, if that’s the issue you are experiencing: