Liquid roof.....so many reviews, good and bad

We used the Liquid Roof from EPDM. While it did do a good job of sealing the roof, in short order the surface turned splotchy gray and looked as bad or worse than before we coated. Keep in mind that it is only the looks and the actual material is still sealing the roof. The manufacturer refused to acknowledge the problem or do anything about it. This was 2 years ago. We did the coating, not because of leaks, but a precaution on an 18-year-old roof that has no leaks at this point. We are very disappointed in the appearance and how the manufacturer has NOT responded. I seriously wonder if they will stand behind the product if there is a failure since in our case the "Warranty" means nothing. The splotchy surface issues began within a matter of a few months and to this day continue to get worse. At this point, the previously white roof is now covered in gray and darker areas all over. Chuck