Struggling to Get the Split Function to Work Consistently

Hi, everyone. I'm wondering if anyone knows of a fix for this. I'm using a Windows laptop and trying to split a section of a video into several parts that might each just be one second long. But when I right click to bring up the editing menu, most of the time "spilt" is not shown as an option.

Also, using the supposed keyboard shortcut "s" does nothing either. I've also tried pressing it with "shift" and "ctrl". Does anyone know of a solution? I haven't found one by searching this subreddit or Google, YouTube, etc.