Gif transparent background cannot remove previous frame

[naive]

Hey guys, I'm trying to remove background on an animated gif and cant wrap my head around why it doesnt work

I've tried
convert -delay 5 see6x8x24.gif -coalesce -fuzz 10 -transparent black -loop 0 -layers optimize -limit thread 8 new2.gif
convert -delay 5 aa.gif -coalesce -fuzz 10 -transparent black -loop 0 -layers optimize -limit thread 8 new.gif
convert aa.gif -layers Dispose canv.gif
convert aa.gif -coalesce -dispose previous -limit thread 8 opt2.gif
convert aa.gif -coalesce -layers OptimizeFrame opt.gif
convert see6x8x24.gif -fill none -opaque black -dispose background -limit thread 8 aa.gif

and these are the animations im workin with:
removed background
still with the background intact

Could anyone enlighten me what am I doing wrong?

[naive]

oke I've found how to do it myself! This worked ->
convert -dispose previous aa.gif nobg.gif

Still i don't understand how come if i run this command ->
convert aa.gif -dispose previous disp2.gif
it doesn't work!

What is this sorcery!?

[snibgo]

"-dispose" is a setting that modifies what happens when a GIF is read. If you set the setting after the GIF has been read, it's too late.

In future, please always say what version of IM you use, on what platform.