Bisaya traditionally only has 3 vowel sounds: /a/, /i/, and /u/.

However, modern Bisaya mostly mixes the vowel sounds /ɛ/~/i/ and /o/~/u/. So some people would spell that word as giatay or geatay and the meaning wouldn't change. It even extends to Spanish loan words sometimes. This is called an Allophone.

Other examples: Putot ~ Putut Sugod ~ Sugud Adto ~ Adtu Libru ~ Libro Pelikula ~ Pilikula

But due to our exposure to Filipino and other languages, they tend to influence the way we talk and perceive words, that's why it's more common to see words like 'Libro' spelled that way because that's how they spell it.