i replaced it with a new one and the tip broke off

If the new one is the right one and matches up dimensionally with a proven right sensor, then the trigger ring would be my guess. That is the toothed ring around the crankshaft. The ring must be damaged or broken or altered or bent such that it is sticking out, hitting your sensor. It may stick out only when spinning by centrifugal forces. If not by feel or eye, you may have to turn the crankshaft and watch the teeth pass the sensor. Good luck. Let us know what you find.