Whenever people have issues with a gun doing something other than normal, I like to suggest they have another person (that has solid fundamentals and experience) shoot the gun to see if they too can replicate the problem. That way the owner isn't going down rabbit holes trying to find solutions to problems that likely don't exist. Understand, I'm not saying definitively it is something you are or are not doing. Rather, it's just what I like to check first.
Generally, weak ejection on an otherwise stock gun is one of two things, the ammo or the shooter's grip absorbing the recoil rather than allowing gun to perform it's cycle properly. The extractor of course could be dirty but on a service weapon, they can easily go over 1,000 rounds without cleaning and still be expected to be functional.