Zwave to Zwave JS migration fails

I’m trying to migrate to Zwave JS given that Zwave will soon be removed from Home assistant, but the migration fails. The migration wizard fails to start zwave JS and when I do that manually, all nodes are there but none except the Zwave stick can be reached.

I think the problem is that I did not have a network key set in the old config (from Yaml) and that breaks the flow. Could that be and how can I fix that?
I have a lot of zwave devices, it will be a lot of work to readd them manually (let alone adapting all my automations and scripts)…