Desktop Numbers (Windows 10) formula cannot reference different sheet? regular-expression-string of REGEX.EXTRACT can only reference same sheet?

I need help with formula of Apple Numbers Function REGEX.EXTRACT argument regular-expression-string reference another sheet (to centralize my Regex expression to single Sheet; so other Sheets can use same regular-expression-string).

However, said editing exits immediately after I switch to another sheet to a cell as regular-expression-string; instead of said cell value, the formula ends up without regular-expression-string and I am getting error "isn't a valid regular expression).

This problem does not happen using cell of same sheet (for regular-expression-string); said formula does reference cell of same sheet as regular-expression-string.