Missing Response Body While Calling Appian API

Question

Hi Experts,

I'm trying to add validation on my Appian Portal Page which doesn't support Regex Functions and hence I have created a Web API which is validating weather entered IP is valid or not and calling it on the UI using an Integration Object, when I test the API using Postman, I receive the correct response. However, when I use Appian's Integration Object to call the same API, the response body comes back without any value.
Valid Test Value: "1.1.1.1" 
Postman Response: {
    "ipInfo": true
} 
Appian Response:  HTTP/1.1 200 200
Date: Thu, 02 Jan 2025 13:43:42 GMT
Content-Type: text/html;charset=UTF-8
Connection: keep-alive
Server: Apache
Strict-Transport-Security: max-age=31536000; includeSubdomains; preload
Cache-Control: private
X-Trace-Id: a1956c41e9dd44f6226e475d8d145803
Referrer-Policy: strict-origin-when-cross-origin
X-Frame-Options: SAMEORIGIN
Content-Security-Policy-Report-Only: style-src 'unsafe-inline' 'self' https://web-assets.appian-cdn.com; child-src 'none'; script-src 'self' 'unsafe-inline' 'unsafe-eval' https://web-assets.appian-cdn.com; object-src https:; frame-src https:; img-src https:; default-src 'self'; font-src 'self' https: data:; report-to /suite/rest/a/logging/latest/csp/report;
Content-Security-Policy: report-to /suite/rest/a/logging/latest/csp/report;
Vary: Accept-Encoding
Set-Cookie: JSESSIONID=E39CE1C3B5B14568DBD7ADBC0B200225.node1; Max-Age=0; Expires=Thu, 01 Jan 1970 00:00:10 GMT; Path=/suite; Secure; HttpOnly; SameSite=None; Partitioned; HttpOnly
Set-Cookie: JSESSIONID=E39CE1C3B5B14568DBD7ADBC0B200225.node1; Path=/suite; Secure; HttpOnly; SameSite=None; HttpOnly
X-Robots-Tag: none
X-XSS-Protection: 1; mode=block

var hasSiteWideBanner = "true";
  if (window.APPIAN) {
    window.APPIAN.bannerInfo = {
      hasSiteWideBanner: hasSiteWideBanner === 'true',
      bannerMessage: "###TESTSERVER###dev",
      bannerColor: "#666666",
      bannerTextColor: "#ffffff"
    };
  }

function isInIframe() {
  try {
    return window.self !== window.top;
  } catch (exception) {
    // if in cross-origin, cannot access window.top
    return true;
  }
}

body.appian-body {
  background: #ebf1f7;
}

body.appian-body.mobile-landing {
  background: #fff;
}

.appian-body .message {
  color: red;
}

.appian-body form .field input {
  color: #333;
  border-color: #ccc;
}

.appian-body .submitButton {
  background-color: #E8E8E8;
  border: 1px solid #B0B0B0;
  color: #333333;
  font-size: 11px;
  font-weight: bold;
}

.appian-body .login_background {
  background-color: #416b88;
}

.appian-body .login_box input[type=text]:focus,
.appian-body .login_box input[type=password]:focus {
  border: 1px solid #1d659c;
}

.appian-body .button_box_links a:active {
  border-color: #1d659c;
}

.appian-body #back_link,
.appian-body .button_box_links a,
.appian-body .logoutForm #returnLink {
  color: #1d659c;
}

.appian-body .button_box_links a:hover,
.appian-body .button_box_links a:focus {
  border-bottom: 1px solid #1d659c;
  color: #1d659c;
}

.appian-body .btn {
  color: #1d659c;
  border: 1px solid #1d659c;
}

.appian-body input.iBlueButton {
  border: 1px solid #1d659c;
  background-color: #1d659c;
}

.appian-body .btn.primary {
  background-color: #1d659c;
}

.appian-body .btn:active,
.appian-body .btn:focus,
.appian-body .btn:hover,
.appian-body .choice_pair input[type=checkbox]:focus + label:before,
.appian-body input.iBlueButton:active,
.appian-body input.iBlueButton:focus,
.appian-body input.iBlueButton:hover {
  box-shadow: 0 0px 5px #1d659c;
}

.appian-body input.iText:focus {
  border: 1px solid #1d659c !important; /* ASI styles using !important to set blue border color */
}

.appian-body .logoutForm #returnLink:hover {
  border-bottom: 1px solid #1d659c
}

.appian-body #back_link:hover {
  color: #1d659c;
  border-bottom: 1px solid #1d659c;
}

.appian-body .choice_pair input[type=checkbox]:checked + label:before {
  background-color: #1d659c;
  border-color: #1d659c;
}

.appian-body .mobile_landing_links {
  color: #777;
}

.appian-body .mobile_landing_links a {
  color: #1d659c;
}

.appian-body a.mobile_landing_button.primary {
  color: #fff;
  background-color: #1d659c;
}

.appian-body a.mobile_landing_button.secondary {
  color: #1d659c;
  border: 1px solid #1d659c;
}

Appian for TELUS (Cloud)

###TESTSERVER###dev

if (!isInIframe()) {
      document.getElementById("systemMessages").style.display="block";
    }

Use local or SSO login?

Local Login

SSO

Invalid Test Values: "1.1..1" 
Postman Response: {
    "ipInfo": "Entered IP Addresses either Invalid or Private IP Addresses :  1.1..1"
}
Appian Response: HTTP/1.1 200 200
Date: Thu, 02 Jan 2025 13:38:47 GMT
Content-Type: text/html;charset=UTF-8
Connection: keep-alive
Server: Apache
Strict-Transport-Security: max-age=31536000; includeSubdomains; preload
Cache-Control: private
X-Trace-Id: 9fe1f66a83c2146ab13212fcbb7f72b9
Referrer-Policy: strict-origin-when-cross-origin
X-Frame-Options: SAMEORIGIN
Content-Security-Policy-Report-Only: style-src 'unsafe-inline' 'self' https://web-assets.appian-cdn.com; child-src 'none'; script-src 'self' 'unsafe-inline' 'unsafe-eval' https://web-assets.appian-cdn.com; object-src https:; frame-src https:; img-src https:; default-src 'self'; font-src 'self' https: data:; report-to /suite/rest/a/logging/latest/csp/report;
Content-Security-Policy: report-to /suite/rest/a/logging/latest/csp/report;
Vary: Accept-Encoding
Set-Cookie: JSESSIONID=B4D59D4F1C55293A4680DF7C4EB24A9F.node1; Max-Age=0; Expires=Thu, 01 Jan 1970 00:00:10 GMT; Path=/suite; Secure; HttpOnly; SameSite=None; Partitioned; HttpOnly
Set-Cookie: JSESSIONID=B4D59D4F1C55293A4680DF7C4EB24A9F.node1; Path=/suite; Secure; HttpOnly; SameSite=None; HttpOnly
X-Robots-Tag: none
X-XSS-Protection: 1; mode=block