So all of the above unfortunately didn't work for me. If the problem still exists after you've tried it what might help for you is resetting the System Management Controller by pressing shift + control + option + power button for a few seconds and then releasing it.
More info on this on apple's support website
Answer from Maniflames on Stack ExchangeHello! I have a question...
Recently, I had to purchase a new Mac because my last one broke; however, the keyboard copy/paste does not work as the old one did. Is there some setting I need to adjust to fix it? Here is the problem:
The basics are that copy/paste are command+C and command+V. Those work fine. But on my last laptop, I could shift+command+V to paste and have the format fit my text. My new laptop doesn't recognize this... how can I fix it?
Command C / Command V not working. - Apple Community
Shortcut not working Mac (Command C & Command V)
CMD+C Doesn't work for copying | MacRumors Forums
command v doesn't work - Apple Community
Why are Command-C and Command-V not working at the same time?
What to do if Command-C is not working with an external keyboard on Mac?
Does Ctrl+C work on Mac, or do I need to use Command-C?
So all of the above unfortunately didn't work for me. If the problem still exists after you've tried it what might help for you is resetting the System Management Controller by pressing shift + control + option + power button for a few seconds and then releasing it.
More info on this on apple's support website
I found that under System Preferences, Keyboard, Shortcuts, App Shortcuts, I had 'Paste and Match Style' selected for ⌘ + V. I don't recall doing this but maybe I just forgot. This should have been a valid option but instead of pasting and matching the style, the result was it didn't paste anything.
Get a new keyboard.
This is a duplication of your original posting from 4/17:
Suddenly copy and paste function has stopped working (on MacBook Pro)
Please don't submit the same issue multiple times. Continue the discussion in the original thread in order to avoid confusion & duplication of effort.