Thanks for the question.  

If you followed the label direction on application rate, watering it in, and did not have a large rain event following application, you should have had success.  Timing could possibly enter the picture if it was in late June that you used this product. Have you recently checked to be sure you have grubs?  Brown patches may be due to other problems or could be that they have yet to recover from an earlier infestation.  Drought damage and other problems can look similar.  If you have less than five grubs per square foot treatment is not require. A spring curative followed by a preventative next season would be a good next step.  If used properly, these products can be save and effective. Follow the label, it is the law. Check out the following links:

• https://www.canr.msu.edu/news/how_to_choose_and_when_to_apply_grub_control_products_for_your_lawn
• https://www.canr.msu.edu/news/do_grub_control_products_work
• https://www.canr.msu.edu/uploads/files/Mow_highRS.pdf

I hope this helps.