PyBaMM Version

24.1

Python Version

3.9.17

Describe the bug

Following the Coupled Degradation Mechanisms example, The results seem to have changed between (1) stable/latest/v25.4.0 and (2) v23.5_a.

This seems to be related to the change in solver to idaklu, as the example now adds solver = pybamm.IDAKLUSolver(). This is the only change to the example I've noticed, but the results are very different.

I have been using the Casadi solver on slow mode and can reproduce the example in the v23.5_a docs, but fast mode causes issues. Perhaps this issue with IDAKLU is related?

I'd like to know which results are correct and what solver/solver options I should be using.

Steps to Reproduce

See the Coupled Degradation Mechanisms example and compare between (1) stable/latest/v25.4.0 and (2) v23.5_a.

Relevant log output