I’m using a MacBook Air. The Check for Update option is no longer available; perhaps it has been relocated.
I’m clicking on the gear icon in the lower left corner, then “General”. The option was once available, but it has now been removed.
Version: 8.27.3 (287).
Same here! 
It’s like they don’t trust us to manage updates manually anymore. I think they moved everything to automatic updates now. But tbh, I wish there was at least an option to toggle it.
LOL, sounds like typical software devs trying to “make things easier” by hiding stuff we actually use. 
Try checking System Preferences > Software Update—maybe they integrated it there?
Yeah, same issue. I just let mine update on its own now. I think they removed the button to avoid users being stuck on old versions. If it’s annoying you, you could try reinstalling the app—might bring back the update option.
Nah, no point reinstalling. The “Check for Update” button is definitely gone for good. I read somewhere that their new policy forces silent updates for better security. Kind of annoying, but I guess it’s safer this way. 
Yo, I had the same issue! Go into Activity Monitor and make sure there aren’t any Nord processes stuck in the background. If it’s all clear and still no luck, might wanna reach out to support—they can push the update manually if you’re stuck on an older version.