The Today screen is a page to the left of the first home screen which is dedicated to hosting widgets.
It is possible to have a large number of widgets, in which case you can scroll up and down the page to reach more.
On occasions, VoiceOver's three finger swipe up or down to scroll the page does not work, leaving the user stuck in place.
Steps to reproduce
Go to the Today screen.
Place VoiceOver focus on a widget. News, Stocks and ScreenTime are some widgets where I have seen this happen most regularly, but it can happen on others too.
Explore the content of that widget.
Swipe up with three fingers to scroll down, or down with three fingers to scroll up the screen, as appropriate. depending on your current location.
The screen fails to scroll.
Swipe left or right to navigate through the page and return to where you want to be.
If trying to scroll back to the top, double-tap on the status bar instead.