The code was putting a coma instead of a dot for values over 1000$. Analytic was not tracking those sales. analytics.php file with fix :

if ($totals['class'] == 'ot_total') {
$analytics_total = number_format($totals['value'], 2, '.', '');
$total_flag = 'true';
} else if ($totals['class'] == 'ot_tax') {
$analytics_tax = number_format($totals['value'], 2, '.', '');
$tax_flag = 'true';
} else if ($totals['class'] == 'ot_shipping') {
$analytics_shipping = number_format($totals['value'], 2, '.', '');
$shipping_flag = 'true';
}

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