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My guess is that it is still a bit stiff because it's new. Until the weapon is worn-in a bit, may I suggest loading from a locked slide by pulling the slide to the rear with the non-shooting hand, and releasing it to snap forward from the full rearward position. It will give the slide a bit more velocity and momentum due to a more highly compressed action spring, and may help fully chamber that first shot more reliably. If it happened mostly near the end of a shooting session, when the gun may have been fouled with firing residue, then perhaps adding a drop of lube to critical areas part-way through the shooting session may also help the reliability; the need for this will also go away once the gun is smoothed-out/broken-in a bit.
Originally Posted by StorminNorman
You could ask for more suggestions in the General Semi-Auto sub-forum, where many of the auto shooters hang out.
"Placement is power" -- seen in an article by Stephen A. Camp
(RIP, Mr. Camp; you will be remembered, and missed)