I am curious, why you can’t use the Orbi as a Router? I ask because you have gone ahead and replaced the Apple Tower Base Station and are still running into issues, so maybe the issue lies a step back the chain and it’s due to the Mikrotik?
I have not heard of the Mikrotik router previously but I have seen similar Orbi setups work well with Roon. Would it be possible to have the Mikrotik act only as an access point in a non-listening Room and use Orbi as the Router? Since the settings for the Mikrotik are obscure and hard to configure as you mention, could it be blocking multicast from properly happening (and thus our RAAT protocol)?
Also, I just want to confirm the issue to prevent confusion on my end, I gather that the full network topology looks like this, please correct me if I am mistaken:
Mikrotik router (Ethernet) -> Orbi RBK50 (Mesh) -> 2 Orbi Satellites
Orbi RBK50 (WiFi) -> Core (Lightning) -> Library RAID Volume – [Question - What happens if you connect the Core via Ethernet?]
Orbi RBK50 (Ethernet) -> Mac Mini Roon Bridge (USB?) -> Endpoint?
One of the Orbi satellites (Ethernet) -> Airport Express -> Amplifier + Speakers
Same Orbi satellite (WiFI) -> iPhone X (Lightning) -> Apple Headphones?
You are having issues with the:
- Core sometimes not playing both TIDAL content and Local Content in Roon
- The Mac Mini (running Roon Bridge) sometimes not playing both TIDAL and Local Content in Roon
- The iPhone X often not playing TIDAL content and Local Content in Roon
If this issue is not affecting local content I would have suggested taking a look at DNS but since both Local and TIDAL here seems affected, I believe the issue most likely lies with the Mikrotik as it’s the one thing in the system you haven’t changed yet.
Either that or there is a firewall located on the Core somewhere that you’re not aware of, I would check to see if you by any chance are using the app “Little Snitch” as I have also seen reports of this app preventing Roon from operating properly.
Please let me know your thoughts regarding my suggestions.