Her Kinetic Carbine description says the damage amp is of your current weapon damage, but does not increase with intensifying mag weapon damage increases.
Intensifying Magazine buff falls of nearly immediately as you stop shooting, Carbine requires few seconds to charge amp.
So if you use Carbine immediately after shooting you should keep buff but will not get dmg amp or you wait for amp to fully charge and you won't get magazine buff.
If you have clip of your happening it would be helpful.