Hi,
The consistent-topology-changes experimental feature does not yet support upgrades. I.e. if you start with a cluster without the feature, and then try to enable it, the cluster will end up in some undefined state.
To get a functioning cluster with consistent-topology-changes, you need to bootstrap it from scratch with this option.
But remember that this is an experimental feature, it’s not production ready. It’s under heavy development with backward incompatible changes happening every week. It’s fine to play with it with clusters that you’re going to discard.