Navigate to:

data:text/html, <script id="worker1" type="javascript/worker"> console.log('a', 'b'); //only 'a' will be logged </script> <script> const blob = new Blob([ document.querySelector('#worker1').textContent ], { type: "text/javascript" }); new Worker(window.URL.createObjectURL(blob)); </script>

Open DevTools, notice two logs, one with only the first argument 'a'.

Refresh the page with DevTools open, only one log appears.

It looks like the Log.entryAdded event for workers doesn't contain all the information, and that DevTools console is using the deprecated Console domain.