System Preferences - Keyboard - Shortcuts
Go through every category and see if there's any other conflicting shortcuts. Make sure you check if there's any relevant global (applies to all apps) shortcut entries in "Application Shortcuts". If you want to make absolutely sure, press the "reset to defaults" button.
I had the same problem just now, but I eventually found out that it was Blink1Control2 (USB notification light - great stuff <3) that occupied that particular shortcut. My bad though - I didn't realize changing the default hotkey would reserve it globally. It was a bit hard to find, since the keyboard bindings is registered through the app and not the OS.
However, if you have no luck in the System Preferences, I would recommend to check which apps and/or services you have running. The menubar in the top right corner usually provides some clues. Check if any of those apps have keyboard shortcuts enabled. Then close the apps systematically and restart Chrome to see if it's working.
One more thing: You could also run "Activity Monitor" to see all your currently running apps (if there's anything running that you're not able to see straight away). Just type "act" in the Spotlight search box, and it will show up, most likely).
Good luck 👾