Custom size
o 6 pages across
o 1 page down
o Auto cropping: on
o Print orientation: lock
Some points I notice from the screen shots:
The preview is saying 3x2, you need 6x1
The image size is 24x11. It should be 24x6
Not specifically related to you initial query but you appear to have borderless set. This will not give you accurate matching of the poster elements; that may not matter for your 6-image frame where the images are separated.
See my attached screen snaps where I simulated your situation. I was very careful to ensure the image (crop) was exactly in the 24x6 ratio.
I have borderless set too. LT28 is the Preview on the main screen and LT27 is the Full Page Editor Size tab. I'm not sure why the FPE shows huge top & bottom borders but I don't think it'e relevant in this situation. I can't check this out with an actual print preview at present because my main PC is being repaired at present.
Edit: make sure you do not have Info selected on the Job Properties.
Terry