I have an Echo Dot Gen 3, connected with OpenHAB version 4.2.0.
I’ve set up the Echo Dot’s volume channel as a dimmer, linked to an Echo_Dot_Control_Volume item. Changing the volume shows a volume change in the binding logs, but no such change is reflected in the Amazon device, and pausing and playing the audio resets the volume item back to its original state.
I saw this topic (https://community.openhab.org/t/echo-devices-not-updating-the-volume-channel-when-changed-on-the-device/), and followed the instructions to install the SmartHomeJ add-on instead, but it seemed to make almost no difference.