I’m posting this in case anyone else runs into this problem, to save them some time. (I know that @rraisley has also had this happen to him).
Early this summer I installed my own PWS, an Acurite 5-in-1. Worked just fine with Weather Underground until the middle of August, where for a couple of weeks it recorded 83886.07 inches of rain per day, and then automagically (that’s a technical term for IT folks) fixed itself. It started again on Dec. 7. I went out of town for 3 weeks for Christmas thinking it might automagically fix itself again, but no such luck. The daily recording on WeatherUnderground always looked ok, but the weekly and monthly were messed up, and that is what Rachio was picking up. Started looking at it closer, and I noticed that on days when it recorded precipitation, the total accumulated amount was correct at 11:54pm, but at 11:59pm it showed 0. Checked the Acurite device’s time, and discovered that it was now one minute faster than my phone was showing. Set it back one minute to match my phone time, and all is well with WeatherUnderground again. My guess is that the Acurite (unlike it’s name would make you think) runs ever so slightly fast, and the time got out of sync. Since it is hooked up to the internet, I would have thought it would have picked up the time from there, but silly me!!!
Good news is that it appears to be fixed.