tidyverse pubh's cross_tab - doesn't recognize column name

Question

Hi I have a dataframe of COVID symptoms and COVID diagnosis:

    dta <- structure(list(fever = c(0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 0L, 
0L, 0L, 0L, 0L, 1L, 0L, 0