Lousy spring. jams and stove pipes occur - Lasermax Guide Rod Red Laser Sight for Glock42

It worked for a few rounds, then jammed and had some stove pipes. Took it back apart and had a gunsmith look at it. He said the spring was not strong enough to hold it in position. He put it back together and it worked for a few rounds again. Then it started with the jamming and stove pipes. I have never had any trouble with my Glock 42 until this.