Scrollbar is not show, how to fix this?

[nickp-real]

pmenusbar highlight

cmp config
onedarkpro config

[fitrh]

The scrollbar only shows when the completion items are bigger than the height of the completion window, try setting your 'pumheight' to a small enough value like 3

For me, with lua-language-server and :set pumheight=5, typing s gave me enough completion items to show the scrollbar

[nickp-real]

still doesn't work

[fitrh]

Make sure you have this

window = {
  completion = {
    scrollbar = true,
  },
}

Although I think it is the default

[fitrh]

And make sure you have a sufficient number of completion items to get it scrolling