A string formatting function is passed a real value for an integer format specifier, which will force the value to round to an integer.
Update the format specifier or add an explicit cast if the conversion is intended.
module fly;
initial $display("%d", 3.14);
endmodule
module fly;
initial $display("%f", 3.14);
endmodule
module fly;
initial $display("%d", int'(3.14));
endmodule