I dont know if thats the problem and Im sayi g from my own experience when it comes to generatin/converting pdf files on windows not mac. I had similar problems and using newer version of ghostscript library( Not sure how it works on Mac) and setting some greater dpi for pdf (300-400 dpi/ppi) solved my problem. You could also check if pdf background isnt transparent (if it is then try setting it to not transparet if that is possible. I never used laz report so im just guessing