Roon Core Machine Mac Mini (M1, 2020) 16GB RAM, 1TB HD Library files stored on external 12TB G-Drive Pro via Thunderbolt Roon Remote Machine iMac (Retina 5K, 27-inch, 2020) 128GB RAM, 4TB HD Networking Gear & Setup Details All connected via ethernet to BT HomeHub Connected Audio Devices …

Thanks! Looks like Amphetamine is the way to go. Shame it needs a third party app to solve the problem though.