Well, when I run my code, I always get the rhat to be at 1.0 for the priors and yes, they do converge, however, sometimes there are divergences, but it sometimes be between 2 to 15 for each chain and in total, from last run, like 35 and lower. Furthermore, when it comes to the posterior predictive sampling in the prediction, it like 1.2 to 3.11 while correction 2.5 to 6.0 for the rhat.