When you replace the preferences you are deleting the set you have and replacing with a new default set (using the keyboard shortcuts), or you can replace with a customized backup set you previously saved. See Replace Your Preferences
two days after and a new update it was working back again.
I think it was all related to the preferences.
@Rob: I was using command-Shift and it always works when the black selection tool is active. And also selecting and dragging to create a copy of the object.
It was just strange and frustrating.
Thank you for your answer!
Sharing this information to help others avoid the hours I spent searching for this answer. If (1) trashing/replacing the defaults and preferences and (2) uninstalling and reinstalling doesn't work for you, as was the case with me, there may be a conflict with plugins running in some other programs. I did this:
1. Delete defaults and preferences following the instructions here: Replace Your Preferences
2. Uninstall and reinstall the program
3. Close all programs and reboot. Open inDesign before anything else.
That is what finally worked for me. Agreed with OP that this is a "dumb problem."