Is it obligatory to make up fasting for someone who apostatized from Islam then returned to it, and does this include the days whose certainty of being due is doubted?

Scholars have differed on the ruling regarding a renegade's making up for missed acts of worship after repentance:

First: What was missed before apostasy: Malikis: He is not obligated to make them up if he embraces Islam, unless he apostatized with the intention of avoiding the make-up, in which case it becomes obligatory. Jumhur (majority): They hold that making them up is obligatory, because abandoning worship is a sin that remains after apostasy.

Second: What was missed during the period of apostasy: The renegade is not obligated to make up for missed prayers, fasting, or zakat during the period of apostasy, because repentance nullifies what came before it, and Islam erases what preceded it. They cited the Almighty's saying: "Say to those who disbelieve, if they desist, what has occurred in the past will be forgiven them," and the Prophet's (peace be upon him) saying: "Repentance nullifies what came before it, and Islam erases what was before it."