My plotter is a gps map 7408, software version 9.00

I've been trying to load the Altantic bluecharts.

I've installed the charts on my laptop, I have the forums mapsource version. 6.13.7.

I can see the charts in homeport and mapsource, they seem to be unlocked.

When I export the selected charts in either mapsource via send to device, or map install, some img files are placed in a garmin folder on the sim, I place this in the plotter and it seems to load the maps without error, however when I zoom in I just see either land (yellow) or the shaded world map.

Really lost as there are so many different guides and steps and tools, can anyone help me please?