Red stain appeared after prespraying residential carpet.

[JandRsCarpetCleaning]

We were pre-spraying a residential property synthetic carpet with an alkaline prespray dand this pink started to appear. We then rinsed that area and the pink rinsed out and went away. Two days later the pink came back so we tried it with our upholstery tool and more did come through the tool but it didn't budge. Any suggestions on what to try next or if its not fixable?

Thanks