There is no difference between Krsna's body and Narayana's body. Therefore although they (Jaya and Vijaya) visibly entered the body of Krsna, they actually reentered Vaikunthaloka as the doorkeepers of Lord Visnu

Expressions researched:
"There is no difference between Kṛṣṇa's body and Nārāyaṇa's body. Therefore although they visibly entered the body of Kṛṣṇa, they actually reentered Vaikuṇṭhaloka as the doorkeepers of Lord Viṣṇu"

Srimad-Bhagavatam

SB Canto 7

Whatever their position, certainly Jaya and Vijaya always thought of Kṛṣṇa. Therefore at the end of the mausala-līlā, these two associates of the Lord returned to Kṛṣṇa. There is no difference between Kṛṣṇa's body and Nārāyaṇa's body. Therefore although they visibly entered the body of Kṛṣṇa, they actually reentered Vaikuṇṭhaloka as the doorkeepers of Lord Viṣṇu.

SB 7.1.47, Translation and Purport

These two associates of Lord Viṣṇu—Jaya and Vijaya—maintained a feeling of enmity for a very long time. Because of always thinking of Kṛṣṇa in this way, they regained the shelter of the Lord, having returned home, back to Godhead.

Whatever their position, certainly Jaya and Vijaya always thought of Kṛṣṇa. Therefore at the end of the mausala-līlā, these two associates of the Lord returned to Kṛṣṇa. There is no difference between Kṛṣṇa's body and Nārāyaṇa's body. Therefore although they visibly entered the body of Kṛṣṇa, they actually reentered Vaikuṇṭhaloka as the doorkeepers of Lord Viṣṇu. Through Lord Kṛṣṇa's body, they returned to Vaikuṇṭha, although they seemed to have attained sāyujya-mukti in Kṛṣṇa's body.