shinyBS Popover not working without using bsButton()

Question

I am struggling with a weird behavior of shinyBS-popovers within insertUI(). It seems like the popover is only added if a bsButton() is included somewhere.

You can play around with the example below. As soon as you uncomment any bsButton(...), the popover works.

library(shinyBS)
library(shiny)
library(shinyWidgets)

# UI ---------------------------------------------------------------------------
ui <- basicPage(
    actionButton("show", "Create Input"),
    # uncomment me!
    # shinyBS::bsButton("id_button1", "A Button"),
    fluidRow(
        tags$div(id = 'placeholder',
                 style = "min-height: 400px;")
    )
)

# Server -----------------------------------------------------------------------
server <- function(input, output, session) {

    # insert checkbox when clicked
    observeEvent(input$show, {
        insertUI(selector = '#placeholder',
                 ui = tags$div(id = "id_div",
                               # uncomment me!
                               # shinyBS::bsButton("id_button2", "A Button"),
                               shinyWidgets::prettyCheckbox(
                                   inputId = "id_checkbox",
                                   label = "Click Me!"
                               )),
                 immediate = TRUE)

        addPopover(session, "id_div", "Hello", "Stranger")
    })
}

shinyApp(ui, server)