The fan on the left is directly connected to an electric socket.
Your photo shows the S1 using a only a single split connection to the PSU and that's usually a big no-no for these things.
It should work this way. I've seen pictures with this setup. I won't destroy this new PSU. Not before i'm 100% sure.
Thx. Maybe it is the controller. I'm not an expert but the fan is working on both blades if i disconnect the controller. Whenever the controller is between, the fan is not working. I will wait for an answer from bitmain.
EDIT: And there is vid on youtube where the fan is working from the beginning. That's why i think it should.