Location data (both "last known"/saved and live) not being displayed on mobile devices.

[VictorGil]

When opening the URL (https://mylocation.devaction.net) on any browser on both Android and iPhone devices and after the user has agreed to trust our self-signed certificate, the location data (both "last known"/saved and live) is not displayed.

Workaround for some Android phones:
For it to work, the user needs to manually add the SSL certificate to the device's trusted certificates/CAs store (which does not seem to be possible in all devices because Android has enhanced the security recently).
The self-signed certificate can be downloaded from here.