Cannot add accent marks on character, as accent marks immidiately appear before the next key press

In short, I am trying to type the acute e (é) character. For some reason, on my office computer (Linux Mint Cinnamon), I cannot write the character as I am used to. The way I would normally do it, is by pressing AltGr\\, release, e. The problem with this system is that the acute character ´ immediately appears, and the e character after it. So instead of é, I get ´e. It is the same for other characters, for instance, if I wanted ñ, I would press AltGr¨, then n. But in reality, I get ~n. Then ~ immediately appears. My keyboard layout is Norwegian.