The token/participant record does not get "closed" with "Q" status on quota end. The token record gets no update on token exit at all.

Tracked the last "working" version to 6.15.5+250724,
6.15.6+250818 adds a timestamp to Complete field instead of "Q"
6.15.7+ don't change the record any more

Seems like somewhere along the changes the $SESSION['survey' . $iSurveyId]['token'] gets wiped.
in the Qotas model if (
$sClientToken
&& in_array($sAction, [
Quota::TERMINATE_VISIBLE_QUOTA_QUESTIONS,
Quota::TERMINATE_VISIBLE_AND_HIDDEN_QUOTA_QUESTIONS,
Quota::TERMINATE_ALL_PAGES
], true)
) {
submittokens(true);
}
$sClientToken is empty and the update is not done.