I recently purchased Sram Rival groupset and I just finished installing it to my bike. However, there seems to be something wrong with the right shifter. When I try to shift to a larger cog, the shift lever gets stuck in that position and I then have to pull it back to neutral position. At first it shifted ok but now for no apparent reason it started doing this.

So, do you think that there could be something wrong with my installation or is this just a faulty shifter? Is there anything that I could do with it or should I send it for warranty? I purchased this from other country so I think sending it back would cost quite a lot..