Meta Ads Custom Audience Issue

I am experiencing an issue with my Meta Ads custom audience. Despite having 12,000 unique visitors to my Shopify site in the last 180 days, the custom audience for all website visitors only shows between 2,700-3,200.

The problem persists across other custom audiences as well, including Add to Carts and Purchases. My pixel and conversion API are functioning correctly.

I have already verified my pixel installation, and I manage my Meta Ads through Facebook Ads Manager.

I am seeking a professional who can diagnose and resolve this issue. Please bid if you have the necessary skills and experience.

Please refer to the screenshots.