If you add strings to the Before/After fields for Separator in the Chapter Numbering options, they do not appear unless there is a numbering.
Per the help, if numbering is set to None, "Only the character or symbol defined in the Separator fields appears at the beginning of the numbered list".
Thus, even with no numbering, the strings in the Before/After fields shall be displayed.
Works fine with the 7.2.1 version installed on Xubuntu (21.04). Was working fine with portable 7.0.5.