R shiny datatable columns width making no sense

Question

I have a shiny app and one page has three tables next to each other as you can see in the attached screenshot. I set the width of each column to be 3 as explained in the shiny documentation and again, as you can see from the screenshot, these tables are too tight even though column = 3 should be enough to avoid tables content to be compressed and printed over multiple rows. I can't customize (and I don't even think I should) the column width to pixel. Is there a basic parameter I'm missing somewhere? Also, why is Shiny printing this horrible bottom border black line for each of these tables? Thank you

    ShinyApp(
        ui = fluidPage(
                fluidRow(column(align = "center",3, DT::dataTableOutput("table1")),
                         column(align = "center",3, DT::dataTableOutput("table2")),
                         column(align = "center",3, DT::dataTableOutput("table3")))     
        ),
        server <- function(input, output) {
          output$table1 <- renderDataTable({
                 df <- datatable(df,
                   rownames= F,                   
                   caption = 'Call info',
                   options = list(scrollX = F                                  
                                  , lengthChange = F                                  
                                  , paging = F   
                                  , autoWidth = T
                                  , pageLength = 5
                                  , info = F 
                                  , searching = F  
                   ))
              })

output$table2 <- renderDataTable({
                     df <- datatable(df,
                       rownames= F,                   
                       caption = 'Call info',
                       options = list(scrollX = F                                  
                                      , lengthChange = F                                  
                                      , paging = F   
                                      , autoWidth = T
                                      , pageLength = 5
                                      , info = F 
                                      , searching = F  
                       ))
                  })
output$table3 <- renderDataTable({
                         df <- datatable(df,
                           rownames= F,                   
                           caption = 'Call info',
                           options = list(scrollX = F                                  
                                          , lengthChange = F                                  
                                          , paging = F   
                                          , autoWidth = T
                                          , pageLength = 5
                                          , info = F 
                                          , searching = F  
                           ))
                      })
                })

Screenshot: