There are two things you probably should consider:
1. Anything new takes time to develop and that's not as much about slowing down your progress it just takes time to develop it
2. Having solid fundamentals makes said new thing easier to develop and helps progressing faster
However, the second point is no guarantee that that's always the problem. So you can check on your fundamentals but it's not guaranteed that it suddenly makes you progress faster. Certain things are simply harder than others