Can a defendant appeal his no contest plea against the finding that he was not mentally competent to enter a plea?

Defendant's request for a certificate of probable cause essentially claims the plea was invalid because defendant was not mentally competent to enter a plea, and furthermore, he was never informed by the trial court or his counsel, of the consequences of his no contest plea. But, defendant's guilty plea and the denial of his request for a certificate of probable cause limit the potential scope of defendant's appeal to "grounds that arose after entry of the plea and do not affect the plea's validity" or "the denial of a motion to suppress evidence under Penal Code section 1538.5." (People v. Maultsby (2012) 53 Cal.4th 296, 299, fn. 2.)