Patch selection

This is probably an easy question, but i have read the manual over and over and still think what im trying to do is right, according to the manual.

I turn the Super 6 on.
The patch button is lit.
I press say, bank D and patch 4.

Bank D is solid lit, patch 4 is flashing

It’s a bass sound.

According to the manual, to access the second bank, i need to now press Bank D again and it will start to flash - which it does. But the bass sound is still the same sound as before and when i press patch number 4 - nothing lights up on patch 4 and the sound doesn’t change?

Im pretty sure I have done something wrong, but i cant see what it is? Maybe there isn’t 2 banks for each letter and Im trying to access a preset that doesn’t exist.

The second bank is empty until you save something there

Thank you, much appreciated.