Isn't accentuation a sticky key? Like, hit the accent first, and then the key to accentuate? For example I hit ´ followed by e to produce é (or ´ (space) e to not accentuate when i want the accent as ´e instead).
Pressing them at the same time feels like it would fail depending on your (or your keyboards, or your OS') timing (and I actually just tried this here: éééeéééééé´´eééééééééééééé´´eée´- most of the time it works, but often I get it backwards or not at all)

That's how it works here. If I hit the keys simultaneously, it is pretty much random whether I get an accented or non-accented letter whether in Word, notepad, mIRC, etc.