I had the same problem with some BC mags. I began loading 15 rounds for a bit instead of 25. Then after about 10 uses I began loading 20 rounds instead of 25 for about 10 uses. I kept the mags loaded between range trips and they work 100% now. The springs just come really really strong from the factory now
The good news is the springs will likely last a long long time because they are over strength. Long term it's a good thing