Roon Arc Crashes with Bluetooth On

I am running Roon Arc on a Samsung S21 Ultra. When conected to Android Auto it works fine so, happy days, tunes in the car. However, if I try and use it out and about it crashes (app closes) as soon as I try to play a track. By random trial and error, I have discovered that, if I turn off Bluetooth in the Samsung settings it works OK. Not ideal when you want to use headphones! Is this a known issue?