Please think about what you are doing before mechanically trying things.
1. If you have data in first differences, the observation equation needs to reflect this. See
2. Also, your output data has an endpoint problem. The last two observations are gigantic for some reason.
3. Why is your prior mean for the shock processes 1, i.e. 100 percent? A one standard deviation shock would then increase the observed series from e.g. 0 to 1. But the data has at most value of about 0.2. See "Remark 10 (Scaling With a Factor 100)" in Pfeifer (2013): "A Guide to Specifying Observation Equations for the Estimation of DSGE Models" at https://sites.google.com/site/pfeiferecon/Pfeifer_2013_Observation_Equations.pdf
4. Given your observables, eps_a_os is not identified. See the flat line for the likelihood in the mode_check plot.