Issues with accented characters

Hi there!
I’ve run into a weird issue and I honestly don't even know where to start fixing it. On one of my computers, accented characters won't type correctly unless I first type two regular letters, backspace them, and then try again. Only then will the accents work.
The original keyboard is an Xbox one, so I tried switching to a USB keyboard, but the exact same thing happens. It makes me think the problem is somewhere in the system software, but what could it be?

I'm guessing you already went through and double-checked all your region, language, and keyboard settings, right?