LED Bars in Pixel Map

You need to patch a server channel, and layer channels. Then set your width and height.  Once you have this established, you have to highlight the grid in  order to assign your start channel or address. You can patch by channel or address and set the start of left to right, top to bottom, columns and rows.

eos doesn't understand, that they are multiple "sub-units" within this fixture. it doesn't matter if you're in group18 mode. you will have to trick a bit. i would suggest:
-leave it patched as it is.
-in pixel mapping, for each pixel use a Generic > LED RGBW 16b personality and patch it by address (not channel).
-in Live, set the intensity of the patched channel to Full, it's the master intensity for the rest of the fixture.
-and last but not least you will have to make sure that all color values of the patched channel are at 0 when you want to use pixel mapping (as Live and pixel mapping are merged together HTP). with do that by running a cue or by changing the home values (either in patch or with the home preset).