In the 19th and early 20th centuries, some yatis, despite being fully eligible and part of the Shankara tradition, could not become heads of their guru mathas. Their names appear in legal and historical records of Shankarite institutions. Their claims for the gadi had led to long legal battles causing many hurdles including serious financial hardship to the duly installed Mathadhipatis. Some of them eventually established new Advaita mathas.
More details soon.