P2CE's menus are able to be navigated using the arrow keys, but this is completely invisible aside from secondary behaviors caused by JS (such as the save preview appearing next to the resume button). Connecting a controller and pressing a button that isn't mapped to anything like Y will make this selection visible temporarily before disappearing again when the arrow keys are pressed. It seems that Panorama uses the same selection logic for controllers as for the arrow keys but P2CE is only making it visible when a controller is the last input device for some reason.
P2CE's menus are able to be navigated using the arrow keys, but this is completely invisible aside from secondary behaviors caused by JS (such as the save preview appearing next to the resume button). Connecting a controller and pressing a button that isn't mapped to anything like Y will make this selection visible temporarily before disappearing again when the arrow keys are pressed. It seems that Panorama uses the same selection logic for controllers as for the arrow keys but P2CE is only making it visible when a controller is the last input device for some reason.