Did Brown have a Constitutional right to have a competency hearing before he plead guilty?

QUESTION(S) PRESENTED 1. Did Brown have’a Constitutional right to have a competency hearing before he plead guilty, where Brown was granted two (2) court orders for a mental evaluation : [1] on July 20, 1999 (that the defense filed; and, [2] on November 12, 1999 (that the Prosecutor filed) 2. Does the issue of "being denied a competency hearing” overcome all procedural barrs in Mississippi through the except law Smith _v. State, 14950 3d 1017, 1031 (48)(Miss. : 2014)(quoting Rowland vy. State, 4250 3d 503, 507 (Miss. 2010) 3. Did Mississippi Uniform Rule Circuit and county Court Practice 9.06 exist before ° Brown plead guilty in 1999; thus should be applied to. Brown's case today. 4.