Here's the pump curve you have.
Friction loss for 500 feet of pipe at 50 GPM is about 22 feet of head, so if you are indeed not lifting the water higher than about 2 feet, the pump should be pumping out somewhere between 40 and 50 gpm. I am assuming the entire discharge line is 2" PVC. So, when you say the water is flowing out, but definitely without a massive force, I'm assuming it is not close to that level of flow. Note that elevation can be hard to actually see. and the internals of a buried pipe can be hard to determine. So, the friction drop across the 500 feet of pipe may be higher than what the tables show, and the elevation may be higher at the discharge end than it appears. 500 feet is a long way to visually see any elevation difference.
Theren is also the possibility of the impeller having damage, but it is still being able to pump some amount of water.
That's about the only thing I can say at this point.
Friction loss for 500 feet of pipe at 50 GPM is about 22 feet of head, so if you are indeed not lifting the water higher than about 2 feet, the pump should be pumping out somewhere between 40 and 50 gpm. I am assuming the entire discharge line is 2" PVC. So, when you say the water is flowing out, but definitely without a massive force, I'm assuming it is not close to that level of flow. Note that elevation can be hard to actually see. and the internals of a buried pipe can be hard to determine. So, the friction drop across the 500 feet of pipe may be higher than what the tables show, and the elevation may be higher at the discharge end than it appears. 500 feet is a long way to visually see any elevation difference.
Theren is also the possibility of the impeller having damage, but it is still being able to pump some amount of water.
That's about the only thing I can say at this point.