Run Xibo Player Options(where you specify the CMS address and key), on toolbar Help->About
So, basically, when there is nothing scheduled(or schedule is invalid) your device will display default layout.
If default layout is invalid then it will display splash screen.
Just to confirm your Download Window start/end time are set to 00:00:00? (which means it’s always open)
If your device is displaying your default layout (assuming nothing else is scheduled) and you schedule simple test layout that for sure is valid (checkmark in CMS) then after 60s your player should know about this schedule and download necessary files then display your test layout.
Perhaps your default layout has a really long durations? Which can cause the scheduled layout to be ‘missed’.
Please see this topic about Durations and this article Scheduled Layouts not working