Remotes won't connect to Qnap Roon Core

[BlackJack]

There is an known issue for the QNAP app:

QNAP Core Authorization Notice

We’ve seen a few reports that, due to some recent changes in our latest update, some customers with QNAP Cores are needing to re-authorize their Core machine. If you see the Authorizations screen after updating, just choose the Unauthorize option and you’ll be able to continue using Roon like normal! You have our apologies for the inconvenience. If you continue to see issues after doing this please open a new post in #support and our team will help you out as soon as possible. Thanks! Roon Su…

There is also a fix for it:

Fix for recurring authorization prompt

I have put updates for the QNAP and Asustor NAS (which have been sent to QNAP App Center / Asustor App Central) on the roononnas.org website, for manual installation as long as they are not officially published. It should fix the recurring authorization prompt after NAS reboot, introduced in Roon Server build 571.

Until the fixed version is available in the QNAP App Centre you have to live with the current situation or manually install the fixed App:

1.7 update problems with Roon Server on QNAP

Download the updated app from roononnas.org Login on the QNAP Open the App Center Click on [grafik] (top right) Click on Browse and select the just downloaded file; click on Install [grafik] Confirm by clicking on OK [grafik] Set the mark on “I understand the risks and want to install this application.”; click on Install [grafik] Wait until the installation has finished.

I hope this helps.