Hello Robert
The handwriting in some of the early burial registers is quite difficult to read and your John Nixon does appear in the online index, but is listed as John Wilson. Also the first person to be buried in Grave F228 is Norah Dixon (sic) in 1882. Her death is registered as Dixon, but it seems a bit of a coincidence.
I am arranging for the John Wilson error to be corrected, but it may be a while before it appears online.
Brian