Video Length stuck at 1:30?

I just started editing videos and am doing this for a friend. The video needs to be around 3 Minutes long.
I got to 1:30 and am unable to proceed. Is that the max for the videos or do I need to change a setting? Thank you for any replies!

Edit:I have a red Ex when I’m trying to put more video or audio into the timeline.

This (unable to drag-n-drop into timeline) is a known bug that is mostly fixed in the latest version (v16.11 or later). However, it appears that it is still possible to trigger this bug. There are a few workarounds including restarting Shotcut, using Timeline toolbar buttons, or using keyboard shortcuts.