Catalina on late-2013 iMac, newly net installed OS. If I use keyboard viewer then if I press either right or left-⌘ (command key) then the keys in the Keyboard panel both show outlined in Red. SO, something works with the left-⌘ (command key)...
If I use the standard Spotlight shortcut ⌘ (command key)+space bar it ONLY works if I use the right-⌘ (command key), nothing with the left one.
If I go to Preferences > Keyboard & Shortcuts tab I can highlight the key sequence and creat a new one: left-⌘ (command key)+J say, it sees and records that. If I try to change that back to left-⌘ (command key)+space nothing happens, like no space key was pressed (Keyboard shows the cmd keys outlined but no flash for the space bar). I CAN re-define it fine with the right-⌘ (command key). This behaviour of no apparent Spotlight was there right from the first login after install [my habit is left-⌘ (command key), took ages to notice right-⌘ (command key) worked!]
Does this make any sense? Can I fix it? Can the command key be masking out the space bar press somehow? (this seems to be the evidence of the Keyboard viewer test)