This is a permission issue
** (connman-gtk:7668): CRITICAL **: 14:20:26.840: Failed to connect to connman: GDBus.Error:org.freedesktop.DBus.Error.AccessDenied: Rejected send message, 3 matched rules; type="method_call", sender=":1.2349" (uid=1000 pid=7668 comm="connman-gtk") interface="net.connman.Manager" member="GetTechnologies" error name="(unset)" requested_reply="0" destination=":1.451" (uid=0 pid=3010 comm="/usr/bin/connmand -n --nobacktrace --nodnsproxy")
For now, i don't found the fix.
As you can see, the connection with dbus is made perfectly.