I would need to see a specimen or a good photo of the raster pattern to confirm your identification. However, assuming you are correct that the grubs are Asiatic Garden Beetle (Maladera castanea), there is some evidence that they are tolerant of some insecticides. We don't have any research from turfgrass settings, but in field corn, higher rates are needed to reduce damage from Asiatic Garden Beetle (AGB). I think it is also possible that your July application may have just been a little too late to control the AGB grubs. This is a late-emerging species that starts laying eggs in July. Neonicotinoid insecticides contained in grub control products take some time to be absorbed into the plant and they may not have been at high enough levels to control AGB at that timing. 
AGB is challenging to control with conventional insecticides, so if you are sure that your identification is correct, then it might be worth looking into alternative options. Entomopathogenic nematodes (EPNs) are a biological control option for grubs, that can be purchased and sprayed in water using conventional application equipment. The EPN species Heterorhabditis bacteriophora can be used to control grubs in turf as a curative treatment. In other words, it must be used when grubs are present in the soil. The nematodes seek out the grubs in the soil, parasitize them and kill them.

You can learn more about using EPN for grub control in this article from The Ohio State University: https://aginsects.osu.edu/sites/aginsects/files/imce/AGB_EPN_Handout_Feb2020.pdf

To learn more about AGB and its control in Michigan field crops, read these articles:
https://www.canr.msu.edu/fieldcropsent/uploads/files/02agb.pdf

https://www.canr.msu.edu/news/asiatic_garden_beetle_a_new_pest_in_southwest_michigan

https://www.canr.msu.edu/news/asiatic_garden_beetles_may_cause_corn_field_yield_losses_in_sw_mi

https://www.ncipmc.org/webinar-asiatic-garden-beetle-emerging-pest-corn/