Can't scroll back in new Terminal

In the old terminal (the one where commands aren't separated and there's no autocomplete), I can use shift+Pgup and shift+PgDn to scroll through the previous output.

In the new (beta) terminal, regardless of which type of prompt I use, I *can* scroll up and down directly with Pgup and PgDn, but only if I click on the previous command's output with the mouse first (which focuses it and puts a blue border around it.)

Is there a keyboard shortcut to move the focus through the command history or to scroll through everything regardless? 

(I have also tested this after disabling IdeaVim, and it doesn't seem to make any difference.)

Thanks.

(latest PhpStorm 2024.2.1, Build #PS-242.21829.154, macOS Sonoma 14.6.1)