Android mobile App connection problem

Hello,

thank you for your plugin. I would like to provide some kind of live tracking on my wordpress blog but i cannot get the mobile app tracking to work (https://play.google.com/store/apps/details?id=com.CodeCabin.WPGoogleMapsApp&hl=de)
I installed the plugin, created a map, added it to a page. After i entered my site url (with https://), correct map id, some time interval and a marker name to the app it says: “save error: Please ensure that all settings have been entered correctly”.
Is there any debug mode for the app? How to check the (probably Rest?!?) API? Do i have to activate xml rpc? I have a firewall plugin running…probably this is causing the problem…

Please be aware that i deactivated the plugin after my first tests.

Thank you!

The page I need help with: [log in to see the link]