I would consider this a severe bug and pretty much a show stopper for me implementing further work I had planned without custom coding.
It appears the only way I have around this is to add a Delete Item button, which sets a hidden status to “ToDelete” and fires a webhook. When that happens, have custom code that gets all of the linked to items, and go remove them before deleting the item.
I already have plans for code, when a high level item (such as project) is archived then connected items that are related to it get archived.