I created an edge loop so that I can add a groove vertically. Just like the horizontal groove. I want it to be a thiner groove so after creating the loop I pressed G > G to slide along the face. This was the result. I did notice when creating the loop I had to do it twice because the loop didn't go from the top of my model to the bottom. I'm sure that's where the problem is I just don't know how to fix it. How do I fix my faces or edges to go the same way?
I don't know how this fixed it but I deleted these quads circled in red. Then deleted the loop cut and redid a loop cut and it worked. Can you explain why?

