Monkey3:
Using the same code I get the attached.
That's strange, when TEST is low the MAX chip should be in receive mode and the pullup resistor should hold the A line high (on my image it is low but this is probably the logic probe pulling it down) and the pulldown holds the B line low. On your trace A is behaving as expected but B is remaining high.
I used a module that looks like yours but I don't have it with me to check the exact model and MAX chip used.
I'm at work and just happen to have a MAX485 chip (not module) to hand to connected it to using the same scheme and get the same results.
Maybe you should try another MAX485 module/chip.