


I guess you've clicked "service worker" in chrome://extensions, which opens a limited version of devtools for this worker alone, and that is not a bug, although indeed it's inconvenient.To open devtools for the offscreen document you need to click `offscreen.html` link in chrome://extensions either inside the card for your extension or in its details. This will open a full-fledged devtools where you can inspect storage and elements, as well as switch the inspected context between the service worker and the document within the same devtools.