Conversations that are critical which if avoided have the ability to breakdown the very existence of the team.
Whenever you see a breakdown in relationships of a group which leads either to violent eruptions or uneasy stonewalling and graveyard silence in the group tranactions and relationships, the Rip van Winkle leader needs to awaken & realise that it is time to build an environment of trust & safety in which the team has serious conversations around sensitive themes & uncomfortable topics.
Block out masking behaviours. Discourage avoidance of conflicting discussions . No masking or faking..controlling outcomes without engaging all..no ganging up..no negative labelling of behaviours. When such behaviours are not stamped out, they create blocks which stop creation of a pool of common stories from which the group members derive their meaning.
Crucial Dialogues & fierce conversations are critical. You can foster a false sense of pleasantary by blocking conversations or make winners by creating a safe environment in which teams indulge in fierce and crucial conversations.
Indeed teams are made effective one crucial conversation at a time. I suggest that you opt for the later.