Im in an RV and am a stationary camp host. I'm on 50 amp service with a surge and voltage regulator in line. Just last week i noticed food was taking longer to bake, did a temperature reading with a digital thermometer and was 15 degrees low. Have a help request in to support. Did a bit of oven interior cleaning and the temperature seems to be running normal. Any ideas what might be going on? Been in this same spot for years and am pretty sure the power is stable.