bs3: "paper" theme's selectizeInput (single and multiple) missing underline

[MadhulikaTanuboddi]

Issue only on bootstrap version 3

sample code:

library(shiny)
library(bslib)
old_theme <- bs_global_set(bs_theme(version = 3, bootswatch = "paper"))
onStop(function() { bs_global_set(old_theme) })
shinyAppDir(system.file("themer-demo", package = "bslib"))

Check the selectizeInput widgets.

version-3:

version-4