Localization - switch language bug if the new language has the same translation as the original (4.25.3)

We have some strings as follows
English - Orange
Spanish - Naranja
German - Orange
When we switch from English to Spanish it correctly updates to ‘Naranja’. Then when we switch from Spanish to German it stays at ‘Naranja’, though all the other strings change. Our guess is it’s because the new string is the same as the default English string.
It’s not just this one string, it also happens with ‘Manual’/‘Manuel’.
Has anyone encountered this before, and/or know of a fix?