Lifeline subscriber here… I love the concept of ARC but have found it to be for the most part so unreliable that I can’t use it. I have an iPhone 12 Max currently updated to the most recent IOS. I have my Roon core on a NUC running ROCK and my library is on a Synology NAS.
The issues I’m running into is that ARC freezes up all the time. The music usually continues playing but the screen on my iPhone and/or Apple CarPlay freezes up. In some cases the iPhone screen freezes up while the CarPlay screen continues to show time elapsing. When that happens, if I click the forward button on the CarPlay screen, it moves back to the spot where the original freeze occurred. When this happens, the music still continues to play.
One potential problem may be the size of my library. Currently at over 500,000 songs. Regardless I have no issues at home with Roon and this same library plays just fine through Plexamp when mobile.
TIA for your help.