Universal Hex input method invited itself back as standard on my login screen with latest upgrade

Yes, thanks. It was there, no idea where that came from. I spawned another MacBook Pro from the same Time Machine backup which still has Sequoia 15.7.1, and there only the language input sources I defined are there for a couple of alphabetic writing systems. Removing it returns the MacBook Air to expected behaviour. In Spanish, it is "Ajustes de Sistema -> Teclado -> Introducción de texto -> Editar... Todas las fuentes de entrada"

Since upgrading from Sequoia to Tahoe, the login screen of my macBook Air switches to Unicode hex input scheme instead of Spanish after switching the device on, so the password is wrong on first intent if I forget to manually switch it back to correct setting before. The system has been migrating/reincarnating on new hardware for 20 years now, always set to Spanish since the first 2006 MacBook Pro. Removing the Universal Hex input option in the login screen settings in the right upper corner does not help, I have not found anything in the settings after logging in. Where do I switch this off for good and get the Spanish setting back? Not sure whether this is a bug or a feature...

(typo universal hex input instead of unicode hex input)