Is this part of your problem? Do you still have a connection to the QNAP registered?
Alex, I’m new to Roon, but when setting up a mac mini as a standalone Core a few days ago, I found two things caused this constant initializing when remote connecting with Roon from another computer into the Core: First, I had another core that I’d setup before I had the mac mini. Until I logged out of that original core, initialization of the new core continued (can’t be logged into two cores at once unless you have two separate subscriptions). Until I went onto my core machine with Roon running on it, I did not see the message that logging out of the original core was required. Second, if I stop running Roon app on the mac mini but leave the Server software running, any remote Roon machine sees the core initializing. Starting Roon on the mac mini fixes that. I’ve just asked in Support for why this is the case and await clarification.