In order for us to provide better support, we need to see the log generated by citra. This guide will walk you through how you can obtain the log file: How to Upload the Log File
I am unsure if you can currently re-arrange the gamepad due to the latest Citra Android update breaking the ability to customize their location on the screen.
Hi, please try the latest Canary build, there should be a fix that allows you to open up the in-game settings menu using the Back button: Releases · citra-emu/citra-canary · GitHub