Getting different SSL certificates in Java/Browser

I’ve setup Kong with a self-signed certificate for localhost that seems to be served correctly when I visit the site in my browser. (I go to view certificate and it matches the details). However when I make a call from my Java application I get the following default Kong cert instead of my cert:
“Certificate”: {
“certificate_request_context”: “”,
“certificate_list”: [
{
“certificate” : {
“version” : “v1”,
“serial number” : “00 D7 C5 E6 DC E0 A8 90 80”,
“signature algorithm”: “SHA256withRSA”,
“issuer” : “CN=localhost, OU=IT Department, O=Kong, L=San Francisco, ST=California, C=US”,
“not before” : “2018-09-06 09:58:17.000 EDT”,
“not after” : “2018-10-06 09:58:17.000 EDT”,
“subject” : “CN=localhost, OU=IT Department, O=Kong, L=San Francisco, ST=California, C=US”,
“subject public key” : “RSA”}
“extensions”: {

}
},
]
}