Hi there seems to be a new-ish bug where after a leader is created in a Layout which is attached to a model space object, later editing of the leader gives the warning “The RLeaderEdit command broke history on o1 object”
If a leader is a History aware copy, then edits to its text were lost if the parent were modified (causing a history replay and resetting the text to match the parent) So, modifying leader text now just breaks history.