Welcome to our forum!
I noticed the same issues when I first received my WEPS Gen3 Pro, although I suspect the same might occur using the other WEPS systems as well, as they operate in a similar way.
I too noticed fairly quickly that I wasn’t keeping the stones flat against the edge of my knives, especially on my left side. It’s all in your individual technique. First thing I would do is slow down. Focus on flat stone to your blade. If your blade is thin, either re-adjust it, or, what I do is support it a little with my other hand. Everyone does it a little different. You will develop your own method.
I do hope this helps a little. It’s like anything else…practice makes perfect!
Alan
2 users thanked author for this post.