How to make the app fill the window?

When I run my app locally it fills the screen showing all the data.
However when I deploy the app, it only takes up a defined area and you have to scroll to see all of the data:

Is there a way to make the pane scale to the size of the window? I have tried FillPage() but that does not work.

Edit to include ReprEx:

list1 = list(matrix(nrow=25, ncol =25), matrix(nrow=25, ncol =25))
names(list1) = c("Choice1", "Choice2")

  ui = fluidPage(
    tabPanel("tab1", fluid = T,
                 selectInput("Input1", "Input1", choices = c("Choice1", "Choice2"))
  server = function(input, output, session) {
    Data1 <- reactive({
    output$viewTable <- renderTable({

If I run this app on my local machine when I increase the size of the window the values will fill the pane, whereas when I deploy it with rsconnect::deployApp it remains a static size regardless of window size and has to be scrolled across.

Hi, welcome!

To help us help you, could you please prepare a reproducible example (reprex) illustrating your issue? Please have a look at this resources, to see how to create one for a shiny app

Okay, edited to add reproducible example, thanks for the info

So if anyone has the same issue, apparently if I use rsconnect::deployApp on a .Rmd file it will not fill the pane, but when I upload separate ui.R and server.R files it works as intended.