modMail.muteConversation's numHours parameter is ignored

[fsvreddit]

Regardless of the number passed in as numHours, the user will be muted for three days.

    await context.reddit.modMail.muteConversation({
        conversationId: "1xkchm",
        numHours: 7 * 24,
    });

The API docs state that the method accepts values 72, 168 and 672 for 3, 7 and 28 days respectively.