Those are very normal temperatures for the CCR1009. I wouldn't worry in the slightest.
From my experience, it appears that the fan control software tries to keep the CPU temperature in the mid 50s. If you don't even need to spin the fans to achieve this, you must be in a very favourable environment.
For the purposes of comparison, here is one of my CCR1009-8G-1S-1S+ operating in a temperature-controlled datacentre environment:
I think the reason is that the fan(s) are temperature controlled, and your temperature is to low for the fan to start. I see that as soon the cpu temperature is around 53-55 degees the fan seem to start on my device.