The up and down arrows not working correctly in Safari

Question

M1 Mac Mini running Monterey 12.6.5 - Safari 16.4.1

Problem is with trying to use the up and down arrows on a wired keyboard in Safari.

The expected behavior is that every time I press the down (or up) arrow, the web page would move down (or up) 1 line.

Actual behavior is pressing the down (or up) arrow leads to continuous scrolling that ends when it reaches the bottom (top) of the web page or if override by using scroll wheel on mouse.

Arrow keys work as expected in Firefox and elsewhere on Mac.

2nd keyboard behaves identically.

When in Safari reader view, the arrow keys work as expected.

The problem does not exist when I log in as different user.

Any idea on how to fix?

Answer 1

It's a dumb change they made in Safari 16.4.

1. Give Terminal Full Disk Access in the System Settings -> Privacy & Security panel.
2. Quit Safari.
3. Open Terminal and enter: defaults write com.apple.Safari IncludeInternalDebugMenu -bool true
4. Open Safari. Click on Debug menu, WebKit Internal features, and UNCHECK EventHandler driven smooth keyboard scrolling.

Answer 2

Turning on/off the Accessibility Keyboard (or Keyboard Viewer) fixes it.