Using Chrome 119, I see

  SyntaxError: Invalid regular expression: /^(?<year>\d{4})(\-)(?<month>\d{1,2})(\-)(?<year>\d{1,2})T(?<hour>\d{1,2})\:(?<minute>\d{1,2})\:(?<second>\d{1,2})(Z?)$/i: Duplicate capture group name

This happens whenever I insert text to any cell. I just tried inserting "TEST" to a cell on the first sheet, then pushed the Enter key. It also happens when I use arrow keys to move away from a cell I am editing.