For example, I have no problem pronouncing "ender" because it has no elements that have unambiguous pronunciation. I also have no problem pronouncing "centre", because it's a well known word with well known pronunciation. But libre is not an existing English word, and "-bre" does not have an unambiguous pronunciation heuristics, so it's unclear how it is intended to be pronounced.

Not an issue in Spanish because it is (apparently) a word in Spanish.

Another example of a bad naming is Forgejo. Terrible. I'm sure it has very clear pronunciation if you speak Esperanto.