b3.1.2.15 [Ion Classic] Cursor keys insert whitespace instead of navigating in Macro Editor

I tried to edit a macro but couldn't navigate within the editor on an Ion Classic. Cursor keys added a space before the macro text instead of moving the cursor. Tried shift+cursor, alt+cursor, ctrl+cursor and none of them worked.

I was able to edit the same macro on a Nomad connected as a backup using the same user profile so it seems to be localized.

I will try a deep clear when I'm back at the theatre to see if that helps but there was very little activity between installing and using the Macro editor so I'm dubious it will help.