Closing a single position
Every open position on the Trade Desk has its own red Close button. It closes that one (account, contract) pair and leaves the rest of your book alone — the surgical alternative to Flatten all. A confirmation dialog always appears here, and it tells you exactly which of the two cases you are in.
Closing a leader position
Closing a position on the leader is just a leader trade. The dialog says so: "This sends a closing order on the leader account. Your followers close along with it, the same way they copy any other trade." The close fills on the leader, the fill mirrors out, and every follower exits with it, delta-exact. Copying stays on throughout.
Closing a follower position
Closing a position on a follower is different, and the difference is the part worth understanding. A closing order is sent for that position only — and copying for that instrument is paused on that account.
It has to be. The follower's job is to match the leader. If you close a follower position while the leader still holds one, the next reconciliation pass would see the gap and re-open the position within seconds. So the close also pauses that account's rule, and the toast tells you plainly that copying that contract on that account "is paused so it is not re-opened. Turn it back on with the Follow switch."
When you want the account mirroring again, flip its Follow switch back on (Trade Desk or Accounts). The next reconcile re-aligns it with the leader.
If the close cannot complete
A close is an ordinary order, so it can miss — a dead session, a closed market. The copier retries the close on a re-sweep, checking every few seconds against the broker's actual book. If the position is still open after the retries, it raises a loud CLOSE FAILED event in the alerts bell, naming the contract and account and telling you to close it with your broker. It will not pretend the position is gone.
Quick answers
Why did copying stop on that account after I closed one position?
By design, and only for that instrument on that account. Without the pause, reconciliation would re-open the position you just closed. Re-enable it with the account's Follow switch.
Does closing a leader position pause anything?
No. Followers close along with it through the normal copy path, and copying continues.
The close failed — what now?
The copier keeps retrying, and if the position is still open after the retries you get a loud CLOSE FAILED alert telling you to close it with your broker. Do that, then check the row matches before re-enabling anything.