Location required
Set your GHL custom menu link (Embedded Page / iFrame) to include a static location id in the URL.
https://client-cortivo-matter-navigator-staging.up.railway.app/?locationId=YOUR_GHL_LOCATION_IDReplace YOUR_GHL_LOCATION_ID with your sub-account id (e.g. from a working direct link). Do not use {{location.id}} merge fields — they are not substituted in your GHL setup.