It happened to me too after upgrading to Android Studio 4.0, it was fixed after I went to Android Studio > Preferences > Keymap then choice MacOS:
For Mac users:
I went to:
~/Library/Preferences/Android Studio 4.0/options
keymap.xml, which I noticed was not present on the previous version folder.
It seems to have the shortcuts working as expected.
Fixed, it happen because Android Studio 4.0 by default use Intellij Keymap, fixed by change back to MacOs keymap. Android Studio > Preferences > Keymap