It may be possible that the charts are not enabled by default on your device.
To activate the display, proceed as follows:
Open chart window > open top right menu > Chart Options > More Options > enable Shadow Relief.
Also make sure that linen and areas are enabled for chart options > chart categories.
Also make sure that the latest software version of the manufacturer is installed.
(Settings > System > About)
To do this, compare your installed version with the available version from the manufacturer:
downloads.bandg.com/
downloads.simrad-yachting.com/
downloads.lowrance.com/