When manually deleting the preview hst configuration of a branch, the frontend starts to behave erratically and it is likely that by accident you work in core while thinking you modify a branch

We need to make sure that when a -preview of a branch config is missing that we either remove this channel from the project overview (and delete the branch hst config) or instead we need to make sure that it gets automatically recreated AND that the UI in the channel mngr behaves correctly.

Note the only way to get in this state is to delete the -preview of a branch, which should never be done, but we need to be more resilient against this : PS or partners might be used to or have a script that removes -preview configs during a new deployment: This means that branches can become corrupted.