Have you had a direct conversation with them? If not, have one with a line manager, an out of the line technical expert, and a member of HR. Explain specifics,

Have you had a direct conversation with them? If not, have one with a line manager, an out of the line technical expert, and a member of HR. Explain specifics, and how expectations are not being met. Then be silent and see how they respond. Develop an action plan with dates. Mention consequences later, if the action plan is not being followed. Bad things happen to good companies. You must use a process to get out of it.