The cheaper brands of race-body work most all ways never fit properly out of the box , and require some cutting/trimming to fit (some times a lot of cutting and trimming!).
I'm not saying that all of the cheaper brands are junk, just that they require more patients when installing.
I have used several different "cheaper" brands of body work on my race bikes and the fitment problem that you are having with the lower sounds normal.
The best fitting bodywork that I have ever installed has been Shark Skinz. They are expensive, but you get what you pay for.
I recently helped install race body work from the same manufacturer on two different bikes of the same make,model,and year. One set of body work went on with very little cutting or trouble, while the second set required a lot of cutting on the lower to get it to fit properly.
Here is a pic of my current race bike. It has a set of Hot Bodies body work on it. It had a "rattle" can paint job on it,until a friend of mine painted it for me. Some have affectionately named her "The Electric Banana" !
