plotly::subplot annotations titles disappear in R Shiny - r

Question

I have made a Shiny Application which includes an interactive plot via ggplotly in R. For plotting two of these interactive plots together I used plotly::subplot. Subplot works fine as intended, however the titles of the two disappear in the Shiny application.
How can this be fixed?
Relevant Code:
# Define UI for application that draws a plotlys
options(shiny.maxRequestSize=30*1024^2)
ui = navbarPage("Title", theme = shinytheme("spacelab"),
tabPanel("Interactive Plot",
icon = icon("chart-area"),
# Show plots side by side
splitLayout(
plotlyOutput(outputId = "Comparison_Plots"),
width = "1080px",
height = "1280px")))
# Tell the server how to assemble inputs into outputs
server = function(input, output) {
output$Comparison_Plots = renderPlotly({
....
fig1 = ggplotly(gg_plot1, tooltip = "text")
fig2 = ggplotly(gg_plot2, tooltip = "text")
# Plot them together
sub_plot = subplot(fig1, fig2, margin = 0.05) %>%
layout(annotations = list(
list(x = 0 , y = 1.1, text = "Group 1", showarrow = FALSE, xref='paper', yref='paper'),
list(x = 1 , y = 1.1, text = "Group 2", showarrow = FALSE, xref='paper', yref='paper'))
)
sub_plot
})
}
Snapshot from viewer window just showing the sub_plot
Snapshot of sub_plot as shown via the Shiny app

Answer 1

You have to increase the top-margin in layout:
layout(
annotations = list(
list(x = 0.2 , y = 1.1, text = "Title 1", showarrow = FALSE,
xref = 'paper', yref = 'paper'),
list(x = 0.8 , y = 1.1, text = "Title 2", showarrow = FALSE,
xref = 'paper', yref = 'paper')
),
margin = list(l = 50, r = 50, b = 50, t = 100)
)