If you can, you should send it back to the maker for adjustment. But looks like it is not in your options.
It is a bit difficult to understand the situation correctly without knowing the details.
With that said, I would suggest you test the blade rocking. When you open the blade with the lock bar pushed away (unlocked), do you have any horizontal blade play? If you do, you should tighten the pivot little by little, and see if the lock bar settles somewhere.
Another thing you can try is to apply Sharpie on the blade tang and see if that makes the lock engagement 60% constantly and ease the disengagement.
My Spyderchef showed a similar behavior at the beginning. Sharpie solved it in my case. I can still push the lock bar in, but it seems to be the design choice of Marcin Slysz.
Hope this helps at all.