Currently, the default number of slides that appear on the dropdown is 10 slides as shown in the screenshot above.
To display the rest of the slides, you may need to click onto the browser window/tab before you can see the bar on scroll or touch (On TouchPad).
Even if you don’t see the “Scroll Bar” right away please try to scroll on it to make it work.
If that still doesn’t work try navigating by using the keyboard arrows. (Up/Down)
Scrolling anywhere within the dropdown slide list will work.