Adobe ECID not setting up an Unique Visitor ID

[Kshg7030]

Hi All, 

I am using Adobe ECID extension to track unique users across my site. Under this extension I am using adobe Visitor ID (ECID) and combining it with visit Number to form a unique Session ID for my site. However, this is not working all the time. I have a few instances in my reports where I can see either of these 2 values (ECID & Visit number) are coming in as null (since I have not set default value of NA for their respective data elements in Tags).

I am not able to identify any reason for this and this issue is also very inconsistent so not able to replicate it every time. Sometimes a simple Page Load pushes the value, sometimes it does not. 

Any help or guidance is appreciated.

Thanks

[manojsingh-tech]

Potential issues - 

1. Timing of Data Element Evaluation
• If your data elements are being evaluated before the ECID service has fully initialized, they may return null.
• This is especially common on fast-loading pages or when the ECID extension is loaded asynchronously.
2. Missing or Delayed ECID Initialization - If the Adobe Experience Platform Identity Service (ECID) isn’t initialized properly before the rule fires, visitor.getMarketingCloudVisitorID() may return null.
3. Visit Number Dependency - Visit Number typically depends on Adobe Analytics cookies (s_vi, AMCV_, etc.). If these cookies are blocked, deleted, or not yet set, the visit number may not be available.
4. Rule Execution Timing - If your rule is set to fire on Page Load or Library Loaded, it might be too early. Try using DOM Ready or Window Loaded to ensure all services are initialized.
5. Browser Privacy Settings / ITP - Safari (especially on iOS) and other browsers with Intelligent Tracking Prevention (ITP) can block or restrict cookies, affecting ECID and visit tracking.
6. Cross-Domain Tracking Issues - If your site spans multiple domains or subdomains, ECID might not persist correctly unless cross-domain tracking is configured.

use this customer code or delay in your rule to wait until the ECID is available. 

var visitor = Visitor.getInstance("YOUR_MID");
return visitor.getMarketingCloudVisitorID() !== null;