I understand your frustration as I have wells there also. From a geologist's point of view, I can explain part of the situation. Horizontal wells have enormous potential over a very long time frame. The wells come on line at very high rates and then decline rapidly over the next couple of years. After that, they are thought to have potential at those low rates for decades. What is happening is that the frac job fractures the shale horizons in a way similar to a tree root system. Think very large roots close to the well bore, then medium slight farther away and a vast array of very tiny roots that extend for hundreds of feet. That early large production rate is from the large fractures close to the well bore. By years 3-4, the medium size fractures contribute. Takes a while for the molecules to travel the longer distance. Then over time, the molecules travel from those tiny highways over much longer distances. This gives what is called an inverted hockey stick profile. The blade is the first few years and the long handle are the many decades.
Another issue is that companies are constantly trying to figure out the best way to drain the field area. Faster is not often better. They want to make money just as much as we do, but they want to make it over a long time (as do we), so they are constantly trying to figure out the choke sizes on the well and what is the optimum size. Think of the spigot on your garden hose. If you want a gentle stream, you don't turn it on very high. Another good analogy is if you are sucking too fast out of your really cold milkshake. If you suck too quickly, the straw collapses and you don't get any fluids. If you suck at a low constant pressure than that chocolate shake comes right in, but at a low rate.
Your monthly checks are also not aligned perfectly with oil and gas prices. The check for June might be for production in May or April. If oil is high today, but low back in May, then your check reflects that. Same for gas, but it can be delayed by two months or more in timing.
On the DUC's or Drilled and UnCompleted. Many companies did not complete wells due to either the weather cycle since ND gets REALLY cold in the winter, the pipelines were not finished year and the price was low. Minerals owners would like to have better prices for our product, so it is okay for them to bring the wells on line slowly to balanced all those factors.
Hope that gives you a bit of understanding about what is going on. It is normal