Roon on MacOS looses System Output as Audio Zone when start playing

Core Machine

ROCK Version 1.0 (build 227) with Roon Core Version 1.8 (build 790) stable running on PrimeMini 4 with Intel Core 8i7-8650U vPro (NUC7i7DN), 2x8 GB DDR4-2400MHz, 2 TB SSD internal storage

Network Details

I’m located in Munich/Germany, connected via 100/44 Mbit/s DSL.
The network uses DHCP, is fast and stable. DNS is Google.
My DSL router & WiFi AP (Fritzbox 7590 with latest Firmware 07.25, 2,4 and 5 GHz) connects the Roon Remotes (all via WiFi: iPhone 11 Pro, iPad Air, MacBook Pro, all latest firmware and latest Roon software).
The Core is wired via Gigabit-Ethernet to the router, as is the main system network streamer (LUMIN).

Audio Devices

ROCK (Core)
➜ Ethernet ➜
Fritzbox 7590 (DSL Router, WiFi AP)
➜ WiFi ➜
MacBook Pro
➜ Bluetooth ➜
AirPods / Bose

Description Of Issue

I’m using Roon on my WiFi connected MacBook to play music (via System Output). Sometimes I want to also listen to headphones, connected via Bluetooth. When I start playing a track, Roon idles some seconds and then looses the Audio Zone. After some more seconds, the zone comes back. Music does not play (see screenshots).
Playing music via Build-inOutput or through the other zones works without any issue.

2 posts were merged into an existing topic: Bug: Roon stops playing zone A when BT headphone is turned off in zone B (MacOS remote - not playing)