About time zone, it’s important that both CMS and your device are set to the sime timezone, especially regarding schedule.
So download window start/end time is still 00:00 and 00:00 (always open)
So every 10min your device should check with CMS for updates (content/schedule)
To the ‘Last accessed’ column on displays page in CMS, confirm that?
This simple layout that you scheduled is it working now?
Apart from that scheduled layout, I assume you have other layout set as a default layout which presumably is displayed on your device, is there a chance that you have some really long durations set there?
You could also try to update your Android device to R57.
As always another screenshot/picture of status window on that device could be helpful.