Also i am a bit dissapointed as all they keys are not "smooth"
A lot of people think, that MX Browns feel like scratchy MX Reds.
Myself included. It's not a bump, it's a scratch. I ordered a MX brown board and had to send it back the next day, because MX Browns are just garbage.
You think the color of MX Browns was coincidence? I say:It was not! Just think about what else has the color brown .... yeah, right.
Anyways, if you cannot return it, the only way to fix it is soldering.