First, please make sure your camera body/lens is supported HERE.
If you have two images, both shot with the same equipment, and OpticsPro for Photos is unable to apply a module to one of them, then that image has likely been processed. It could have been processed prior to import to Apple Photos, or Apple Photos has applied some corrections prior to sending the image to OpticsPro.
You can find out how to reset corrections made by Apple Photos HERE.
More information about processed images and automatic corrections can be found HERE.