Cancel event is triggering automatically after successful payment

[AnoopSurendran]

Hi, 
I have integrated Paypal on my project, on sandbox mode. It's a javascript based project, (more precisely written in Angular6). I have used a package called ngx-paypal and followed the guidelines from their official documentation https://github.com/Enngage/ngx-paypal. Everything works fine but I am unable to get a response/message upon the process is completed. When I check the network tab on the browser I can view the success message along with the API cart call
However, Oncancel event is triggering. You can see this issue on this stackblitz Link
I opened the network tab and click on the paypal button. The payment process is thriving on the network. The cart api gives success response like 

"ack":"success","data":{"payment_action":"sale","purchaseUnits":[{"amount":{"total":"1.00","currency":"INR"}}],"purchase":{"description":[null],"amounts":{"total":{"amount":"1.00","amount_formatted":"₹1.00","amount_formatted_forex":"1.00000","amount_formatted_number":"1.00","amount_formatted_currency":"₹1.00 INR","currency_code":"INR","forex_in_currency_format":"₹1","field_name":"total"}},"items":[],"shipping_method":"","postBackData":{},"shipping_address_list":[null],"shipping_phone_number_list":[null],"phone_fields":{}},"state":"created","supplementary":{"buyer_set_in_session":false},"payer":{},"partnerIntegration":false,"cartHasInventory":false,"instantUpdateIntegration":false,"grossTotalAmount":{"value":"1.00","currency":"INR"},"flow_context":...}

But soon after the onCancel event is triggering.
Can you please check this. 
While you try to reproduce the issue on the above stackblitz link, please don't login to paypal. Select Pay by debit card/ credit card instead.
Use the country India, Card number some dummy card number. Pin code some 6 digit number starts with 6.