Mock LocationHow do I check that spoofing actually works?
Open any other app with a map — for example, Yandex Maps — and see where it shows your position. If it shows the coordinate you chose, spoofing works at the system level.
Check in another app, not in Mock Location itself: there the chosen point is shown in any case, because you set it.
A sign of working spoofing is the persistent notification in the shade. If it disappeared by itself, the system has stopped the background service; what to do about it is described in the “Troubleshooting” section.
If another app stubbornly shows your real location while the notification is in place, the problem is not spoofing but how that app handles location data — see the separate question about this.
Five checks in increasing strictness — from a location test page in the browser to a check after fifteen minutes with the screen off — are collected in the guide how to check that spoofing works.