@rsiegel I think it’s very easy to reproduce. Actually I had the problem every single time I add a sensor through the ‘+’ button when a sensor is automatically proposed (i.e. when data coming from new channel are acquired).
At this point I get the sensor in the left siderbar, but not in the dashboard, and the added sensor is unusable…
@shramik_salgaonkar not a solution, just a workaround 
I won’t start a new device and re-add manually all the sensors… This was the case when I got 5-6 duplicatated ‘dead’ sensors 