Yesterday while taxying out in the RV-12, the fuel level reading on the Dynon showed zero. I knew there was plenty of fuel in the tank, which the Moeller confirmed, so I took off. After takeoff, the gauge decided there was fuel in the tank after all, and slowly got to a reasonable reading. Then it dropped out for a short while later in the flight after some steep turns (maybe coincidental), but then came back up to level. The sender response has always seemed a bit sluggish. Any ideas why this might be? I don't particularly want to pull the tank or replace the sender, but obviously may have to. The sender was installed as per the plans and the float arm worked smoothly at the time.