Astra Mini Depth sensor not working

Hi there, I am trying to setup the astra mini camera on Ubuntu ROS. However, when I opened up rviz to subscribe to the depth image topics, it seems that I am not getting anything back - no point clouds and a blank black image. Data is correctly published and subscribed (I have double checked with both rostopic and echo) but the depth value is constant around 30. I am able to get data from rgb and ir, and they work fine.

Did I do anything wrong? Or could it be a faulty depth sensor? Is there anyway I can check whether the depth sensor is correctly functioning?