A couple of things to check out. First, make sure the laser stuff is enabled. I know that laser support was not enabled in v509 of the firmware, but I’ve not checked v510. Here I did a diff of the Ramps and Rambo firmware.
The other issue I’ve seen is that some laser users were either failing to get the M3/M4 g-code to work or were getting bad results. When they went to inline commands, everything worked. Take a look at the g-code in the first post of this topic. The code uses the ‘S’ parameter of the G0 and G1 to control the laser.
I’m not sure how your defines are processed. You might also want to check pin 44.