Thanks for the report, Josh, but I cannot really make heads or tails of what the problem is.
In turn 8 of the game you mentioned, you had a starting hand of Copper, Gold, Changeling and 2x Estate. You
bought a tournament that turn, you did not play one (because you had none in hand). I could gain a Copper or Gold from playing Changeling afterwards, without problem.
You write
I get why one can't use Changling to gain another Tournament...it's an odd card that leaves play early.
I
think you mean Changeling (again) instead of Tournament, because the statement doesn't make sense for Tournament, it doesn't leave play early.
What I found in the log on turn 5 is this, which seems to include the log message you are referring to:
(mocked up Josh for clarity, starting hand is 2x Copper, Royal Seal, Changeling, Estate )
Turn 5 - Josh
J plays a Royal Seal and 2 Coppers. (+$4)
J buys and gains a Tournament.
J reacts with a Royal Seal.
J topdecks a card.
Changeling can no longer move Tournament (it already moved).
J draws 2 Coppers, an Estate and 2 Tournaments.
So you
bought the Tournament here, you
did not play it. Because you had Royal Seal in play, you got the option to topdeck the Tournament. Because Tournament costs $3 or more, you also got the option to exchange it for a Changeling from its pile. I (and I assume you as well) were presented with both options (see the attached picture), and from the log it seems you chose the option to topdeck it. That results in 3 things that can be seen inn the log:
J reacts with a Royal Seal.
J topdecks a card.
Those first two are obvious. The third is
Changeling can no longer move Tournament (it already moved).
That means that after the Tournament was moved from your discard to the top of your deck, the triggered abilitiy of the Changelings in their pile could no longer move it, because they "lost track". That's what that line is meant to say. That has nothing to do with (later, in your Night phase) being able (or not) to play the Changeling from your hand (which I was able to do in my replay, to get another Copper or Royal Seal).
So from what I can gather, it seems to me that you were confused by the triggered ability of Changeling, that can be seen in the picture: it says Changeling and shows a little Tournament card.
In reality it represents the ability to exchange the just gained Tournament for a Changeling from its pile. I think you interpreted it as a shortcut for "Play the Changeling in my hand and choose to trash it for a Tournament".
That latter is not valid, as the Tournament is not in play. In addition, you play the Changeling in your hand just like any other card in your hand, by clicking on it.