Well, it may be you're able to connect with people. But at the same time, in your first-round interviews, you're not portraying the type of confidence the law firm expects, or you may be talking about inappropriate topics, or you may be not dressing correctly, or you may be coming across as someone who doesn't want to work hard. These are the main issues that I can think of without seeing what exactly you're doing. Or, you may not know enough about the employer or your practice area. Or, if you're a law student in the last year, you may come across as not having enough interest or someone that they can see giving orders.