I checked and couldn’t find anything specific enough for this. I am using a trackpad as I don’t have a mouse. I know that you can usually use a scroll wheel to look up and down while editing your game, but I can’t because I don’t have a scroll wheel. How do I look up and down?
Under System Preferences → Trackpad section. Make sure you have two finger scroll enabled under the “Scroll & Zoom” tab. Verified this works in 4.14 and 4.15. If you have that set, restarted the engine (just to be sure) and it still doesn’t work then I’d say it might be a version issue however, that would be a guess as I haven’t downloaded 4.13 on my mac.