Effects of Magic Jar on a possessed/catatonic body?

Question

Was recently considering usages for the Magic Jar spell, particularly what occurs when two instances of the spell cast by different people interact, and ran into a bit of a conundrum. There are two cases in particular I'm considering, but both seem tied to the same issue:

1. Two players cast Magic Jar separately, then while in the jar state, attempt to possess each others' catatonic bodies.

2. Player 1 possesses Player 2 with Magic Jar, then Player 3 also possesses Player 2 with Magic Jar.

Since the spell's target is self, it should get around the spell effect stacking rule in both cases, so should be castable. What is in question is the implications of the following line:

On a failure, your soul moves into the target's body, and the target's soul becomes trapped in the container.

While the desire by RAI seems to be that the soul present in the body at that point should be pulled into the jar, RAW makes it pretty clear that the original body and soul are linked regardless of who possesses the body at that point. But if I go by that ruling, then I run into some weird implications such as in the second example above. If Player 2's soul is the only one that moves from one jar to the other, then Player 2's body is now housing the souls of both Player 1 and Player 3 simultaneously.

Has anyone encountered this before? What is the best way by RAW to handle such a situation regarding Magic Jar and souls, and has there been any designer clarifications on the matter?

Answer 1

After further digging, it seems case 2 has been specifically addressed by Jeremy Crawford via Sage Advice:

"If I magic jar a person's body, then can someone try to Magic jar into the body I magic jarred into" - @ZarconistPreist

"The effects of the same spell don't stack on a target. See "Combining Magical Effects" (PH, 205)." - @JeremyECrawford

While this counts as a designer clarification for the sake of being an answer, I have to note that it is still in conflict with RAW, since Crawford's argument is based on the spell not stacking on a "target". Player 1 is the target of the spell though, and the possession itself does not appear to be defined as a spell or magical effect.

Answer 2

Case 1

Magic Jar has no specific rule for possessing an body that has no soul at the time. That would probably mean that the more general rule applies and the first of players 1 or 2 who's body is being possessed must make the Charisma Saving throw. and on failure is moved to the jar of the one that tried to possess. But you and your DM could house rule this that no check is needed until one of the souls tries to go back to its body at which point the check and it's results are applied

Case 2

Your soul possessing the body should count as the current occupant of the body. I would assume that if P1 succeeds at taking over P2 and then P3 tries to take over P2's body with P1's soul in it that P1 would have to make the save or be locked into P2's Jar