Space bar and command key (MAC) won't bring up zoom tool.

On one computer running the same 2017.1.1, I can hold down the space bar and the command key to get the zoom tool     then if I hold down the space bar and the option key I can get the zoom tool .    I have been doing this for years.  But as of today, my main computer when holding down the space bar and the command key, I only get the move tool (which I know comes up when just holding down the command key by itself.   Any thoughts on how to get this back to working the way I had it?

Thanks in advance.

Don