how to save data to my custom column in customer_address_entity

i have made custom column called coord in customer_address_entity using db_schema.xml

<!-- add coordinate to customer address entity -->
<table name="customer_address_entity" resource="default" engine="innodb" comment="Customer Address Entity">
  <column xsi:type="text" name="coord" nullable="true" comment="Coordinate"/>
</table>

to save the data i make an observer but the data won’t save to my new column coord, while if i try to save it to vat_request_date, it works

public function execute(Observer $observer)
    {
        $address = $observer->getCustomerAddress();
        $coordinate = $this->_request->getParam('coordinate', '');

        $writer = new ZendLogWriterStream(BP . '/var/log/debug.log');
        $logger = new ZendLogLogger();
        $logger->addWriter($writer);

        $logger->info('Coordinate: ' . $coordinate);

        if ($coordinate) {
            $address->setCoord($coordinate);
            $address->setVatRequestDate($coordinate);
            $logger->info('Data : ' . print_r($address->getData(), true));
        }
    }

it successfully writes the value of coordinate on the log file

[coord] => -6.198619001508404,106.81663381349182
[vat_request_date] => -6.198619001508404,106.81663381349182

this is the events.xml

<event name="customer_address_save_before">
  <observer name="lime_courier_set_latlong" instance="LimeCourierObserverSaveLatlongAddressSaveObserver" />
</event>