Sounds like an area with strong EM interference. Maybe a stop-light with those underground sensors? or under a high-power line? or near a power transfer station

Sounds like an area with strong EM interference. Maybe a stop-light with those underground sensors? or under a high-power line? or near a power transfer station? or high-power radio antennae? Could be giving just enough weird EM interference to bump the sensor from "enough fluid" to "low" (I know I sound like Scully from x-files but could just be?)