The posterior distributions are just like spikes

I am using Dynare 4.3.2 to apply Bayesian Estimation to CTW (2010) model. There are puzzles in my results.
The posterior distributions are very narrow when I use estimation with mode_compute = 6, compared to priors. They are just like spikes.
Since I don't really know how can I solve?I look forward to any hints for this puzzle I encounter. Thank you!
The posterior distributions are very narrow when I use estimation with mode_compute = 6, compared to priors. They are just like spikes.
Since I don't really know how can I solve?I look forward to any hints for this puzzle I encounter. Thank you!