Works fine for me, Pete ... sounds like the Shift+R key combination is redefined in your shortcut scheme.
In WE, Keyboard Shortcuts, try to assign Shift+R to anything ... and the "Currently assigned to" box will show you if it is mis-assigned (or unassigned). It tells me, correctly, that it is assigned to "Radius (Global)". Cancel out before you really re-assign it of course.
Alternatively, display your scheme in your browser as shown in the attached screenshot, do a find (ctrl-F in IE) and enter "Shift + R" without quotes but with spaces to see what it is assigned to (or maybe it isn't assigned to anything anymore)...
HTH,
Karl
AC 28 USA and earlier • macOS Sequoia 15.3.1, MacBook Pro M2 Max 12CPU/30GPU cores, 32GB