Sampling issue for the Cat Adoptions Survival model.

[DanielJRowe]

I'm trying to reproduce the cat adoptions example from the bonus video but am getting rhats of 2.7 and ess_bulks of infinity with the warning during sampling: "Exception: exponential_lccdf: Inverse scale parameter is 0, but must be positive finite!". Despite these issues, the traceplots look fine and I am getting the same results as in the video. I don't recall encountering this issue when I first went through the course last year.

Session Info:
R version 4.3.1 (2023-06-16)
Platform: aarch64-apple-darwin20 (64-bit)
Running under: macOS Ventura 13.6.3
rethinking_2.40
cmdstanr_0.5.3