Regulator question

[1911Ron]

Today I cooked on my Genesis Jr for the second time and I noticed that my temps would swing upwards of at least 50-60 degrees with the lid shut and no wind, I had the front burner on high and for awhile it would sit at 375, I would check later and it would be 320 or so. I would check later and it would be back up again, I'm thinking my regulator is going bad yes?