Option #3. Wells have a natural decline, so although prices are up, you have less product to sell, so that can also contribute to smaller checks.
Option #4 goes with #2. Sometimes wells produce better for a short while after being shut in if the pressure has built up a bit, sometimes they do not if the well bore gets a bit damaged by the shut in. Sometimes. the operators will turn the wells back on slowly in order not to damage the wells, so the volumes may not be as high as they were before.