I encountered this problem in Rhino 7 yesterday. was doing research couldn’t find a solution.
Enter, delete and escape keys don’t work but everything else is fine
Today I solved it. It’s because there is a pop-up message hidden behind all rhino windows at launch. In my case it’s from a plug-in. Because this window automatically gets covered by rhino itself it remains unnoticeable.
you have to navigate through window’s bar and manually close that window then all the keys are back to normal