@schorsch3000 that’s v1 (old) manager.
Check this one out:

https://github.com/DjLeChuck/recalbox-manager

@mattmame i don't see any bios for gamecube in recalbox needings. Do i need it? Which is the filename?

@tacticalsnail In the Main Menu go to "Controller Settings", "Configure A Controller" and then do the Button Mapping for your Controller.
Have you tried other controls to make sure the problem is not in the controls?

You were right, the problem was related to the ES, I tried again and worked. Thank you!

Thanks for your fast replay @SUBSTRING! Yes I am using an official release, although if I remember correctly the last update I got was the one saying "yolo" in the changelog which was only live for a couple of hours, so dunno about that...
Thanks for your advise on external storage, gonna look into it! chaiuwe