If your P25 Adjust mode is to high above 11 the 396XT will not receive.Try below 11 on your setting and your receive should get better.Play with your setting until you are happy with it.After I played with all of the P25 settings I have found the sweet spot and am very happy.
I agree with W9NEW. My sweat spot turned out to be Manual 7, but Auto 8 works pretty well also. Just got to play around with it. Each of our systems might be a little different.