Is occasional, incomplete obedience to one's parents and delaying the fulfillment of their requests after procrastination considered a sin or a major sin?

Filial piety is among the best deeds, and the Lord's pleasure is in the parent's pleasure, and His displeasure is in their displeasure. Obedience to them is obligatory as long as it does not involve disobedience [to Allah] or harm to the son. If there is customary hardship, it is not an excuse for disobedience. If the son is pious towards his parents and makes a mistake, Allah is forgiving to the repentant (al-awwabeen), those who rectify their intentions and obey Allah in their piety towards their parents after a slip.