Krishna is always present in His eternal abode in the spiritual sky.
The statement agāt svaṁ padam īśvaraḥ indicates not only that Kṛṣṇa went to His abode, but that Kṛṣṇa realized His determined desire. If we say that Kṛṣṇa returned to His eternal abode, we imply that Kṛṣṇa had been absent from His abode and was now returning. Therefore, Viśvanātha Cakravartī Ṭhākura points out that it is incorrect to say in a normal sense that Kṛṣṇa “went back to His abode.” According to the Brahma-saṁhitā, the Supreme Personality of Godhead, Kṛṣṇa, is always present in His eternal abode in the spiritual sky. Yet by His causeless mercy He also manifests Himself from time to time within the material world. In other words, God is all-pervading. Even when present before us He is simultaneously in His abode. The ordinary soul, or jīva, is not all-pervading like the Supersoul, and therefore by his presence in the material world he is absent from the spiritual world. In fact, we are suffering due to that absence from the spiritual world, or Vaikuṇṭha. The Supreme Personality of Godhead, however, is all-pervading, and therefore Viśvanātha Cakravartī Ṭhākura translates the words agāt svaṁ padam to mean that Kṛṣṇa achieved exactly what He desired. The Lord is all-pervading and self-sufficient in fulfilling His perfect desires. His appearance and disappearance in this world should never be compared to ordinary material activities.
Source: A.C. Bhaktivedanta Swami Prabhupada (2014 edition), “Srimad Bhagavatam”, Eleventh Canto, Chapter 01 – Text 06-07
