List of steps to reproduce (step by step, including full links if applicable):

• Due to T306508, you may be able to reproduce this by going to https://no.wikipedia.org/wiki/Spesial:Innholdsoversettelse if you're lucky. That's how I noticed the bug, but because the list is somewhat randomized, you may not see it there.

What happens?:

• CX suggests that you translate [[en:Main Page]] into Norwegian Bokmål

What should have happened instead?:

• The Main Page is not an article (even though it may be in the article namespace), so it should not be suggested.

Software version (if not a Wikimedia wiki), browser information, screenshots, other information, etc.: MediaWiki 1.39.0-wmf.7 (800f261), ContentTranslation 670863b