is it taking 12 hours for your rain sensor to detect the configured amount of rainfall?
my rainbird w2 is delayed but i think it is ok. it takes about 15 minutes of HEAVY rain to accumulate enough rainfall to trip the sensor.
can you test yoiur sensor? can you verify the accumulation rate for the day it was 12 hours delayed and know that it should have tripped earlier based on your sensor's setting?
i dont know what their polling rate is, but regardless of a pws, i like my rachio telling me that my external sensor has tripped, it lets me know it is still working.