Issue with Controller Remap

I’ve been using RetroArch for quite a bit on my Android phones but only recently have I had a device powerful enough to play N64 games. I changed the controller overlay to that of the N64 but for some reason the A and B buttons weren’t mapped to A and B, so I went into the quick menu options to change it. Pressing the button in the remap options cycles through the different options, instead of being a list like it should, but it ends at one of the buttons and there is no way to go back, only forward. It doesn’t loop either, it’s just stuck at the last option. I tried to long press but that didn’t work. Am I doing something wrong?