You definitely got a lemon. Failure to extract should be pretty easily fixable but that is sounding like a common problem on them that is more than a flawed extractor.The 4th video, the Jimimini show, he did not even have the gun, he used a CZ 75 as an example to explain what he considered an issue with the Glock copy. Do you think there is any semblance between a SA/DA, eternal hammered fired gun and a Glock clone?
Did you miss the part where he said he didn't have the gun to show it because RI wanted it back ?
I followed up with him and he emailed me to say it took 3 months to get it back, and it must have been so bad that they gave him a new gun.
I have a Stoeger STR9 and a SAR B6 , a lot cheaper than this turd, and DID NOT require any break in nor have any issues , right out of the box like this lemon.
Since you also tried a Glock magazine that means the little cut in the magazine was in the right place, but the magazine catch location is out of tolerance.. That will also make your mags ride high and might be interfering with the feeding, meaning the next round up was a little too high which might cause drag on the action. If the next round up is higher that it should be, then it might be what is keeping the bullet from coming out of the chamber. If it is doing that with both mags, that is probably the issue, the mag release placed too high. You might fix it in two minutes with a file, but i would not it is a new gun, and any file mark would kill the warranty. Make them fix it or replace it.
The fact that many reviewers fired lots of rounds including the one I linked with 1,600 rounds and no major issues, tells me that particular gun was not meant to be yours. I too would send that one back, I usually just fix them myself, but if the mags are not fitting with just a snug presentation into the gun, then it goes back. It's a self defense gun, you cannot have a mag that might not lock in.
That combined with the failure to eject, I would not try to fix it either, it goes back.
I do not know anything about the Stoeger but SAR B6 is just a clone of the CZ ,the Tangfolio, the EEA Witness and the other names it goes by. Those are great guns whether steel or plastic. I would carry one of those into combat anywhere. I am actually wanting to find one of the steel ones in 10mm, under the Tangfolio or Witness brand. I would not mind having one in 40 SW either. My best buddy was a doctor, a surgeon and had lots of money. I taught him how to shoot, hunt and all things guns. When he died he left 100 guns, some very expensive. He had 8 or 9 Sigs and about 90 handguns total. But he did not carry them much. His favorites were the Witness that he had in 9mm, 40, and 45 acp. Just saying he had many $2k pistols but he carried one like your SAR B6. They were among the best buys of any high capacity handgun before all this panic buying started.
Well ship that sucker off and get another and then let us know, you know exactly what to look for. If the magazine catch is cut at the wrong location I would suspect they would just give you another gun.
Let us know how it turns out. Lots of people would prefer a metal frame Glock.