Standard mode is not the way to go. Put the Pro in zero mode, all metal if possible and the sensitivity two bars below max. Try that, if you can keep the Pro stable while raising sense to max, do it. If all metal drives you nuts, play with the discrimination a little. Drop some metal on the ground and dust sense so it just barely does not see the metal. That's where you want to be. Another tip is to get yourself a 1964 or earlier Rosevelt drop it on the ground see what it reads, should be 82-83. Now burry it 4" see what it reads there. Now you have a barometer to go buy.
The pro is an excellent silver machine. The silver has to be there for your coil to go over it. I will be honest with you. I have a CTX 3030 and I use my pro before I use it to find all the shallow coins. Then I will use the CTX to see if there is any deep silver. 90% of your silver finds are going to be 4" or less. Go slow 3-4 second passes with your coil and scrub the ground with the coil guard. Your goina find silver sooner orvlater. If it was easy, everyone would be out there doing it. Research old areas of town, check vacant lots, old houses (with permission), median strips and most of all under old clothes lines.
Good luck----------------you have the right machine for the job------------------it's not the machine.