Originally Posted by JonM
Now that you fixed your first problem your now in the realm of either dirty or unlubed slide release or bad magazine or dirty magazine.
If you can take the magazine apart give the insides a good scrubbing and cleaning with clp. Clean the slide release and lube with clp. Just make sure the magazine isn't dripping with clp just a very very very light coat. If that doesn't work wait for the new mags as the spring in your current one is probably worn
The spring was cheap. so I just went ahead and bought one. I'm going to put it in the gun and see if it improves anything. Even if it doesn't, it never hurts to have a spare.
I also took the gun to the range just to see if the reliability problems were still there. I fired a mag and a half through it without one single problem. The slide even locked back after the last round like it's supposed to and didn't release on it's own when I took out the mag.