hi, domi. this is happening because with shift + click you only select those two frames or cels. in default theme you should see only frame 1 and 30 being darker than the others.
what you need to do is either:
a) drag and select all cels in layer (all frame numbers will get darker) and copy that,
b) just click on layer and copy that. it will paste the whole layer with all its content, or
c) select and duplicate current layer (most likely it has ctrl+d shortcut)
Yeah… what Olga wrote. We are still waiting for Shift+Click to select ranges of frames, layers, cels, colors and tiles. And Ctrl+Click to select individual items.
Also I badly want grid mode for palette colors and tiles and thus rectangle selection ranges.
well, ctrl + click creates the selection, which i find quite useful.
but grid mode in palette would be great. is it somewhere requested / planned as a feature?