shortcut key doesn't work properly
I upgrade to macOS Catalina version 10.15.7 and weird things happen. I'm currently use iMac 2012 and Macbook Air. I upgraded both computers to same Mac OS version 10.15.7 and the Macbook Air works just fine. But, the imac keyboard shortcuts behave weirdly.
First, the Command C for copy stop working. Then, to switch between languages input, I used to use command spacebar, and that doesn't work either.
I know that there a system preference and keyboard tap, which has two options to tick; show keyboard and emoji ... and Use F1 F2 etc keys as standard function keys.
I tick the second option which is use F1 F2 and it works for all other functions but not both the command C and command spacebar to switch the language.
Weirder is that, once I press fn key together with command and C, it works. The text was being copied. But, this doesn't work when I press fn key and command and spacebar, despite it is in the tab shortcuts/App Shortcuts. They both worked before I upgrade to version 10.15.7.
Somehow, I regret ever upgrade to newer OS version because things work as they were before normally and newer upgrade bring mostly headache.
Thanks for your reading and assistance.