Hi Marc, any solution meanwhile?
Having nearly same problem. In my case when changing vom v3.66 to v3.67 my BMS (123/smartBMS) diconnect from sytem. Going back to v3.66 … everything is fine.
Are you using any third party drivers like serial battery?
If you are using modified drivers to access the battery this is the cause of most issues after updates and need to be addressed with the driver maker on git.
This seems unrelated to this topic so I will split it out and move to modifications.