Reverting to null value doesn't seem to work on Inserting multiple Records

In one form, on Validate or Success, I'm creating doing multiple "Insert Records" based on the report of another form.

It took me all day to find the cause of my bug, but I have discovered that once I have a non-null value in one of the Insert Record fields, I cannot pass pass another null value. It will stay with the previous value. It doesn't matter if I try to pass this in the form of a string, integer, or from a list.

I would have something like this in my On Validate

Game = GameSetup_Log[ID == input.Opponent];
for each x in Game.Players_In_Game
{
      Plays = Game_Log[Opponent == input.Opponent && Player == x];

      //calculate stuff for statistics
      .
      .
      .
      //calculator more stuff for statistics
      .
      .
      .

      insert into Player_Statistics
    [
        Opponent=Plays.Opponent
        Player=Plays.Player
        AttemptsAtGoal = AttemptMade
        Blocks = Blocks
    ]
}

As soon as I put a non-null value in any Insert field for Player Statistics, any subsequent insertions in that loop will not accept null, it will revert to the previous non-null value inserted. Say I make 5 records in one loop, and record 1, 2 had Null for Blocks or whatever, record 3 had a value of '3', and record 4 and 5 had null again, 4 and 5 will instead get '3' inserted into the fields instead of the null I try to pass.

Right now I'm using integers types in the fields and null is not the same as 0 because I want to take advantage of Pivot Table reports and averaging and 0 values will throw it off in many cases.

Any suggestions?