I was not sure if the module stores already translated text, or untranslated text?
If latter, the easiest fix would be to go into function BuildOverlay inside the module's script and do this at the very beginning:
message = GetTranslation(message);
this will ensure it always displays current messages in current language. But you have to also make sure to pass non-translated strings in the module's functions from outside.
Since you asked about this on Discord, I'd also mention that the module strangely does not account for room scrolling... Again, the quick fix seems to be this: go again to BuildOverlay,
1) Put this at the beginning:
int char_x = this.x - GetViewportX();
int char_y = this.y - GetViewportY();
2) Replace all other this.x and this.y with char_x and char_y
inside function BuildOverlay.