Currently in stash the description of Automatic Branch merging is the following:

"Enable automatic cascading merging from release branches to their downstream branches. To use this feature, the release branch type must be enabled or the production branch set."

Since we don't need release branches we tried to disable them since we only have a production branch and a development branch with hotfixes / feature branches.
But then stash also disables the automatic branch merging feature, even if the help text says that it should work with only a production branch and no release branches.