ATEM Mini Pro only camera input 2 works

I am new to Atem Min Pro. When I was getting ready to set it up, I plugged the camcorder into input 1, and it did not work. Then, I moved to input 2, and it worked. Then I tested inputs 3 and 4, and they also did not work. The same is true for the output from my splitter from the screen, which works only in input 2. Is my unit defective? Did I miss anything in setting up? Your inputs are appreciated. Thank you.