rmarkdown::render_site does not render what I see with Run

[scotti]

This code chunk

library(tidyverse)
library(RefManageR)
Z_NFS_InvFor2019_GroupID <- "2325523"
Z_TaperFun_CollectionKey <- "S8UMZLZF"
refs <- ReadZotero(group = Z_NFS_InvFor2019_GroupID, 
           .params = list(collection = Z_TaperFun_CollectionKey))
trefs <- tibble(
  refID = names(refs), 
  citation = map_chr(1:length(refs), ~Cite(refs[[.]], .opts = list(max.names = 1), textual = T)),
  title = as.data.frame(refs)$title) %>% select(-1)
kableExtra::kable(trefs)

is in the "index.Rmd" file that is used by the 'site-builder' in RStudio.
If I run the chunk to the console I get the expected result: Cite() produces citations with only the first author.
When it is run building the site

==> rmarkdown::render_site(encoding = 'UTF-8')

it seems to be insensitive to the

max.names

parameter, the basic option of 3 takes effect.
Is it possible to control max.names while building the site?
Many thanks, Roberto