floating point result is wrong

Hello friends, the result of floating point multiplication on hardware 
is wrong. Although it is correct in the simulation, it is wrong when I 
upload it on Cmod A7.

library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
use IEEE.numeric_std.ALL;
use work.float_pkg.all;

entity test_block is
    Port (
        data_in : in std_logic_vector (31 downto 0);
        data_out : out std_logic_vector (31 downto 0)
    );
end test_block;

architecture Behavioral of test_block is
    constant adc_coef : real := 0.000000298023223876953125;
begin
    data_out <= to_slv(to_float(signed(data_in))*adc_coef);
end Behavioral;

I am multiplying the hexadecimal number x"000727AC" (decimal 468908) by 
0.000000298023223876953125. The result should be 0x3e0f1970 (float 
0.139745) as a single precision floating point. It turns out right in 
the simulation.

However, when I upload it on the card, the integrated logic analyzer 
shows as 0x34a8f197 (float 0.000000314682182).

The result that is correct in the simulation is wrong on the hardware. I 
tried to multiply with different numbers, the result is the same wrong. 
Why such wrong results?