In Thor: Ragnarok we see that Loki was on Asgard impersonating Odin since Thor: The Dark World (post credits scene) while he put Odin in a house for the elderly in New York on Earth.
Odin did leave the house and vanishes (or dies, if you'd prefer the term) allowing Hela to escape Hel leading to all the events of Thor: Ragnarok.
Since Loki is shown to be in possession of Odin's staff (Gungnir) in the post credits scene of Thor: The Dark World, it can be assumed that Gungnir was on Asgard.
During the final fight between Thor and Hela in Thor: Ragnarok, Thor is seen to be sitting on Asgard's throne holding Gungnir. But after this fight, it is nowhere to be seen.
I cannot be sure if these two appearances of Gungnir (after Odin's death/imprisonment) were actually the real one and not fake (after all, Asgardians love their secrets).
However, assuming that it was the real staff of Odin, was the whereabouts of Gungnir revealed? Looking for all types of answers (in-universe, comments by the writers in interviews etc.)
PS: Not a dupe of this question as it asks about his treasures (like the Eternal Flame, fake Infinity Gauntlet, Tesseract) and not about Odin's staff.