Networking issues causing device not to appear in Roon (ref#B97P43)

Support
1

Hi! What’s not quite right with Roon?

· None of the above quite fits

None of the above quite fits

· None of these quite match

Tell us what's going on

· Networking issues with Roon and missing device

Tell us about your home network

· Environment Setup:
Core/Server: M4 iMac running macOS 15/16 / iOS remote control
DAC/Amp Hardware: FiiO K15 (Firmware: SOC V155 / MCU V95)
Audio Endpoints: Direct USB (CoreAudio / UAC2.0) & Network Streaming (RAAT / Roon Ready)
1. Roon Ready (RAAT) Network Discovery Dropouts
Issue: Over Wi-Fi/LAN, the K15 intermittently drops offline or fails to handshake as a Roon Ready endpoint.
Context: Triggered by recent Apple network privacy/firewall permission updates that disrupt local broadcast discovery sockets (UDP/mDNS). Switching network inputs or toggling between local/network streams can also trigger input-routing glitches on the unit.
2. USB Endpoint Sample Rate Capping (UAC1.0 vs UAC2.0)
Issue: When connected over USB, the K15 defaulted to USB Audio Class 1.0 (UAC1.0), capping Roon's Max Sample Rate options to 96kHz and causing forced downsampling of 24/192kHz files.
Resolution: Toggling the hardware to UAC2.0 mode directly on the K15 allowed macOS CoreAudio and Roon Exclusive Mode to uncap the device up to 768kHz for bit-perfect playback.
3. Proprietary DSP & PEQ Software Control Failure
Issue: Hardware PEQ filters cannot be manually edited via the K15’s front touch screen. Furthermore, FiiO's WebHID control portal (fiiocontrol.fiio.com) and mobile app routinely fail connection handshakes over USB and Bluetooth.
Resolution: Bypassed onboard PEQ by implementing Parametric EQ processing directly within Roon's 64-bit float DSP Engine.

2

Hi @Ian_begg,

Thanks for laying out the network dropouts and the sample rate behavior so clearly.

Can you let us know the exact local time, date, and track the next time you see a dropout? For the sample rate capping, does it stay at 2.0 after you set it, or does it reset every time?

That will help us narrow down whether we are looking at a repeatable playback issue or a setting that is not sticking as expected. Let us know what you see.

3

Hi @Norris,
The issue seems to have been addressed with the latest Roon update, which brought back the device in Audio Settings.

No further issues, thus far. Thanks for responding.