Non curvature irf

Hi,I try to model of 10% increasing in energy prices.and my irf’s is attached.why all variables completely have curvature but inflation at first behave sharply and with no curvature?
Is this a error in model?or other explanations?

As I don’t know the model, its hard to tell. But usually the fact that inflation is a jump variable and then monetary policy rules with interest smoothing cause a subsequent delayed reaction.