Bluetooth page turners no longer work in Apple Books.

Apple changed how the Books app interprets Arrow Up and Arrow Down keyboard signals. On your older software, Apple Books treats Up/Down as a side-to-side flip. On the new software, Apple Books treats both Up and Down arrow keys as a "previous element" command when in a horizontal layout, causing both keys to turn the page backwards. So now none of my Bluetooth page turners work. Does anyone know how to fix this?