In my google chrome for mac, CMD + Shift + r to reload the current webpage does not work?
In most cases, the reason is, that another application does already listening to the same shortcut.


  In my case it was another running application called Be Focused (Pro) which uses the same shortcut (CTRL+CMD+R) defined as a global shortcut per default.


1.) Try to close a bunch of running applications


Try closing all other running applications. Even the apps which has only an icon in the macOS tray area.
Try the problematic shortcut after a restart of Google Chrome (chrome://restart)
If the shortcut works now, you know that at least one of the closed applications listening to that shortcut and prevents it from working in Google Chrome.


2.) Try to open program for program and test the problematic shortcut in Google Chrome (after a restart) if it still works.


  When you found the responsible application, try to adjust their shortcut configuration.