Summary
In thold_functions.php (line ~3452), the type 2 warn-to-normal restoral path is missing the acknowledgment guard that all other send paths include:
// Type 2 warn2normal (missing acknowledgment check):
if (trim($warning_emails) != '' && $thold_data['restored_alert'] != 'on') {
thold_mail(...);
}
// Type 0 equivalent (correct):
if (trim($warning_emails) != '' && $thold_data['restored_alert'] != 'on'
&& $thold_data['acknowledgment'] == '') {
thold_mail(...);
}
Acknowledged time-based thresholds still emit warning restoral emails.
Fix
Add && $thold_data['acknowledgment'] == '' to the type 2 warn2normal send guard.