Here is an endogenous variable, df, in my DSGE model. Its equation is as follows:

The two variables highlighted in red are endogenous variables, while the remaining ones are parameters. The shock response of the two variables is as follows:

Based on the deviations of the two variables in the initial period, I have calculated that the deviation of variable df in the first period is 0.509543.

However, the impulse response curve of variable df indicates a deviation of 0.0018 in the first period.

I am uncertain as to why there is such a discrepancy and what may be causing it. Could you please give me some help? Your help would be greatly appreciated.

I changed the code from "stoch_simul(order=1,irf=100)" to "stoch_simul(order=2,irf=100,pruning)", Then the following impulse response curve was obtained:

However, the gap is still much smaller than it should be.
I’m really comfused.