The right arrow key (→) on my 2017 MacBook Air has suddenly stopped working for all my apps (everything else is fine). I think it is a system or detection problem, but I cannot think of any ideas as to why this happened. It was working just fine a few hours ago. I tried resetting my NVRAM following the instructions in the Apple Support document, Reset NVRAM or PRAM on your Mac but it didn't work.
I am currently running macOS Mojave. I have tried using an external keyboard which reproduced the problem, ruling out any hardware related issue.
What could be the possible causes of this? How do I resolve it?
UPDATE: The right arrow key (→) works in combination with the modifier keys.