Is it possible for each bucket to tip the same? Just did a few tips on mine from factory setting. One side would tip 7.5 to 8.5 ml, other 8.5 to 9.5 ml. Never the same amount each tip. Looks like even cleaned buckets and level gauge the water retention after tip isn't the same each time so with water clinging to the tipped bucket that would add weight needed to tip the high bucket.
My Rainwise lags cocorahs gauge. For spring/summer to date Rainwise caught 96% of Cocorahs. Many times the Rainwise is only .01 off, I have contributed that to the wetting of gauges differently or not quite a full bucket to tip. But if one has many light rainfalls those .01's add up.
Yesterday for example had few periods of showers when gauge funnels would dry in between showers, Coco showed .56 while Rainwise total was .51
Last week a steady consistent rainfall with both gauges showed 1.07