Stovepipe malfunctions, also known as failure to eject, can be caused by a few things. Mostly it comes down to a new pistol with stiff springs, a weak grip, or weak ammunition. Those three are the most common causes with new shooters and/or new pistols.
Three thousand rounds is more than enough than what is needed to break in all the springs in the pistol, so we can leave that out for now.
I'd imagine that it is some issue between a weaker grip and/or weaker ammunition. My suggestion next time out would be to have someone else, like range staff, shoot the pistol and see if the issue presents itself there. I'd also take some heavier rounds like 124gr or 147gr ammunition and run that through the pistol.
Use Google or YouTube to research what a correct grip looks like before going to the range again. Normally you want to press your palms together as hard as you can, and then loosen the grip slowly until they stop shaking. That amount of grip strength is a good place to start here.
The first step is to pinpoint the issue.