Welcome to the block editor, Danny. Most metaboxes show up in that tiny right-hand sidebar, and very awkward it is. (Plus there are some that won’t show up at all…)
I would recommend that you follow the instructions to create an ACF block and assign your field group to that block. You can limit the block to the specific post type, and create a block template so that block is right there in the editor when a new CPT post is created.
Though the fun part is going back and converting over any older posts…
