If a person has appointed a POA that is under duress can the family file guardianship to be appointed through the court?

Filing for guardianship- court appointed or someone in the family, can be done at anytime. The current status of a POA makes no difference. However, if the current POA is doing a good job - unless proven otherwise - or there is strong objection by others - AND they choose to counter for guardianship themselves- the count will look on them as the most viable candidate. But above all the court will want to determine if the principal is competent or not - and what their wishes are.