Apparently you really don't believe this is possible, so I'll will try to explain my issue in detail and the hack that I used to fix it. I won't try to convince you that I know what I am talking about but here goes.
Relax. I'm trying to help here.
Whether this is an extraction issue or an ejection issue is an important distinction. The reason why I'm trying to get as much information as possible is because if this really was an extraction issue, I'd advise looking elsewhere for the cause of the problem. I had a hard time imagining how a loose mag could cause extraction issues. RoanokeReloader (post #16) could have put a hundred pieces of tape in the magwell and his issue still would have been there.
It seems like what you have is a failure to eject issue. This makes a lot more sense. I'd contact Walther and inform them of the issue.
It looks to me like both lperagallo and RoanokeReloader are having Double Feed malfunctions due to Failure To Extract. (Because RoanokeReloader explicitly mentioned Double Feed and Iperagallo said he had to pull the mag out).
The "FTE" abbreviation can be used for either one of the issues mentioned above, whether it is a failure to extract, or a failure to eject, so it isn't as descriptive as it seems, and it doesn't really help much when trying to diagnose issues with pistols. Same with "FTF". There are different steps to finding and diagnosing issues if the problem is a failure to feed issue, just as there are different steps to diagnosing issues if there is a failure to fire issue.
These abbreviations mostly lead to more confusion rather than helping to describe the issue.
I'm pretty sure the OP is having failure to eject issues, while RoanokeReloader is having failure to extract issues. It is much easier to understand when people stop using those abbreviations, and just describe the issue.
Lucky for the OP, that somebody uploaded a youtube video on the same day that he created this thread, but unfortunately, the uploader used the wrong term to describe the issue as well. I was just trying to get some clarity as well, and help the OP if I could.