13 degrees, 19.2 degrees and 23.5 degrees

Hi,

I'm near Southampton and have an existing 80cm dish focused on hotbird at 13 degrees east. I also have a bracket with which I have added another lnb at 19.2 degrees. Both are fine. My issue is I want to add another lnb to pick up 23.5 and I can't seem to pick it up. I'm looking to get the Canal Digitaal channels (and can organise a subscription for that, so no problem that end).

I've posted a photo of the existing set up. The left lnb is receiving hotbird, and the one to the right is...

13 degrees, 19.2 degrees and 23.5 degrees