Hello @Andrew_Yin,
The next time your system is in this state, could you try the following tests?
A) Change the input on your Devialet amp using the Remote. Then try starting playback to the Devialet zone in Roon.
B) Place your Devialet amp back into standby mode using the standby control in Roon’s volume widget. Then try starting playback to the device using Roon.
C) Place your Devialet amp back into standby mode using the standby control in Roon’s volume widget. Once the device has entered standby mode, wake the device using the standby control in Roon’s volume widget. Once the device has fully booted up, try starting playback to the zone in Roon.
-John