I think you had one too many !s in there (for future reference, it's easier to reproduce if you run your code through reprex, as I have in the example at the bottom). With the code as you had it before, I got the warning
Warning message:
Unquoting language objects with `!!!` is soft-deprecated as of rlang 0.3.0.
Please use `!!` instead.
# Bad:
dplyr::select(data, !!!enquo(x))
# Good:
dplyr::select(data, !!enquo(x)) # Unquote single quosure
dplyr::select(data, !!!enquos(x)) # Splice list of quosures