You can redefine your InDesign commands, but much better would be, to use Paragraph Styles instead as any manual overrides cause problems in the long run.
You could have a Mac OS keyboard shortcut overriding your InDesign function. If so, it could be turned off.
Look at System Preferences > Keyboard > Shortcuts, expecially the Services section.
Okay, figured it out. I have a piece of software called "Sip" which can sample HEX values off anything on the screen. Since it's a tray item, it was overriding InDesign's commands. I disabled it while working in InDesign, and it's fixed. Thanks for your inputs!