About year ago Google disabled Geolocation API for insecure access. That is for all web sites running only regular HTTP traffic. Including geolocation button in Extended QGIS Web Client using Chrome web browser or Chrome on Android devices.
To enable Geolocation back in EQWC is not that hard to implement:
RedirectMatch ^/$ https://your-site.xx/
Redirect /gisapp https://your-site.xx/gisapp
So here’s a test for http://test.level2.si/gisapp/eu_demo