I had to remove a few ancient lines in my .profile (I am a user of the old ksh) for changing a couple of keys using
a xmodmap. To wit:

#       xmodmap -e "keycode  22 = BackSpace"
#       xmodmap -e "keycode 107 = Delete"
#       xmodmap ~/.xmodmap

As you can see I commented out those lines

and I regained the funcitonality I wanted.

Those keycodes were for an external keyboard

that died recently, and so keymaps of the internal KB of
the DELL laptop were probably getting clobbered
in an unexpected way.

The xmodmap codes have been obviated by the settings
of the gnome-terminal's Edit -> Profile settings.