It was in a function that is between a undo-able. (Actually, it's in a function (0) that is called by a function (1) that is called by a function (2) that is called by a function (3) that is inside undo-able).
But this set-up is okay with 3012.
~ReignBough~ ARCHICAD 26 INT (from AC18) Windows 11 Pro, AMD Ryzen 7, 3.20GHz, 32.0GB RAM, 64-bit OS