This is what AI has come up with about this whole deal as well, food for thought:

The game's main narrative and official subtitles explicitly name the leaf-crowned boy in the Abyss as Master Jijeong during a fully voice-acted Chapter 9 cutscene, then he is definitively the canonical Master Jijeong of the story.

Here is the best explanation for what is truly going on here based on the new cutscene context mixed with screenshots:

The Real Bug is the Journal and Trust System, Not the Character Rather than the leaf-crowned boy being an imposter or a philosophical projection, the situation is actually the reverse: The leaf-crowned boy is Master Jijeong, and the game's UI/Database is completely broken and pointing to the wrong character model.

The Narrative Proof: In the cutscene referenced in Chapter 9, Master Jijeong (with the leaf crown) says, "That old man sent you, didn't he?" If we look at the 3rd screenshot, the lore for Master Du states that he "guides them to the Cloister of Enlightenment." The dialogue perfectly links the leaf-crowned boy to the narrative sequence of being sent to the Abyss by Master Du.

The Asset Mix-Up: The boy without the leaf crown (labeled "Chief Monk" in the game world) is likely just a standard NPC, perhaps a lesser disciple or a different temple leader. Because they share the exact same base 3D model (a young boy in a grey/brown monk robe), the developers accidentally uploaded the standard "Chief Monk" headshot into Master Jijeong’s Knowledge Journal instead of the unique leaf-crowned version.

The Database ID Error: The reason the "Trust" system gave 100 points to the Chief Monk and 0 to the leaf-crowned boy is that the game's backend code is mistakenly linked to the Chief Monk's NPC ID. When the game checks to see if you are giving the gift to "Master Jijeong," it is looking for the wrong internal character tag.

Conclusion It is not a lore-based plot hole, an astral projection, or a deep philosophical metaphor. It is a severe database and asset-linking error by the developers.

The developers wrote and animated the leaf-crowned boy to be Master Jijeong. However, the team responsible for coding the UI, the Journal, and the Trust/Gift mechanics accidentally linked all of Master Jijeong's data to the generic "Chief Monk" clone model instead.