Mailgun is showing mail opened when it's actually not

I want to know whether emails are opened by the clients or not (I already have a link along with the email but I want to know if they didn't click the link by opening the email and ignoring it).

Using Mailgun API,

I created webhooks and integrated with Mailgun.

@PostMapping(value = "/open-events")    public ResponseEntity<Void> receiveOpenedEvents(@RequestBody MailGunPayload payload) {        EventData eventData = payload.getEventData();        LOGGER.info("Event of type {} received", eventData.getEvent());        //logic removed        return new ResponseEntity<Void>(HttpStatus.OK);}

But my problem is this webhook is called even when the email is not opened by the client.

I also tried calling their Events API but I get the same thing. (The opened event log when the email is not opened)

This is the piece of code for Events API.

HttpResponse<String> request = Unirest.get(API_URL +"/events")                .basicAuth("api", API_KEY)                .queryString("recipient", user.getEmail())                .queryString("event", "opened")                .asString();        return request.getBody();

Below is the screenshot of my webhook from Mailgun Dashboard.

Am I missing something?

PS: The gmail address was used as a client.