Hey, I just saw this post earlier today and wanted to respond. I noticed the same thing when I first got my new Do-Wins and did my OCD examination of them. I've been wearing them about 6 weeks now, and they still have the same behavior. The sole isn't quite level when you examine the shoe by itself. As you press down on the heel of the shoe, the toe pops up in the air. I know this is retarded, but I made a video that explains what we're talking about.
I haven't really noticed that it affects my lifting. Also, perhaps other brands of shoes have this same build. Maybe it's on purpose. I have no idea. I'm by no means the expert.
I just found it peculiar.