I have always assumed that Shift+Ctrl is interchangeable with Ctrl+Shift as a modifier to certain keystroke commands. For no particular reason, I have been in the habit of typing Shift+Ctrl.
Since upgrading to Ubuntu 22.04, I find that only Ctrl+Shift is working.
While I may have to retrain my fingers, I wonder why this has occurred, and whether there is a simple way of changing back.