Pads - can't change the ground symbol - even though library is included.

I have a design that used triangle symbol for ground. I want to change this to the conventional 3-line version of ground (I am going to copy this schematic into another schematic).

However, using CTRL-SPACE to add a ground symbol, then using CTRL_TAB to cycle through the different symbols, does not work. CTRL_SPACE gives me only the triangle, and CTRL_TAB doesn't change it.

It works fine in the other schematic, the one that I want to merge with this older one. It seems that it's something particular to this older file.

I have verified that the $GND_SYMS ground symbol "component" is in the librarary (common), and it does include the correct GND symbol.

Why can't I get the GND symbol using CTRL-TAB?

Thanks