The flow of water into the pool appears to be surging or stopping and starting. Why?
Check the water level in the pool. If the water level is too low, the pump will draw water out of the skimmer faster than water can flow from the pool into the skimmer. The skimmer will empty out; the pump will get a “gulp” of air and then lose the prime. After a few minutes, the pump will regain the prime and the process will repeat itself. If the water level is OK, check that the weir or “flap” in the skimmer can move freely. If it is sticking the skimmer will empty as described above. A defective weir should be replaced.