Digital BW, The Print

I purged my epson 1270 with the mis cartridges...followed a procedure to
print a purge sheet...

then installed MIS ut fsn cartridge for the grays and MIS eboni
black...when I print the purge sheet again all I get is the black
cartridge printing...the other five bars which should be shades of gray
don't print...

any suggestions?

thanks in advance...