No, your radar is not broken.
It is correctly detecting precipitation. The problem is that the precipitation (rain, snow, etc) is evaporating before it reaches the ground because the air is too dry.
The radar beam is angled upward, "looking" several thousand feet in the air, detecting hydrometeors. (Hydrometeor = fancy word for precipitation.) But, the air is so dry that on the way to the surface, those hydrometeors dry up, or evaporate.
This is called "virga." As the water droplet falls through dry air and evaporates, it leaves streaks. Virga is also appropriately referred to as "fallstreaks" and "precipitation trails."
As the precipitation falls through the dry column of air and evaporates, it cools the air around it. Also, it's adding moisture to it, raising the dew point.
As the dew point and temperature get closer to one another, the air is becoming more saturated. Once the air is saturated, and the dew point and temperature meet, we see precipitation reach the ground.
