Not properly spacing commas

[mogsdad]

This rule should provide spacing after commas:

        symbol_then_space: {  // https://regex101.com/r/jB5aN0/4
            expr: /(?:[ \t]+([.,!?;:])(?:[ \t]+|$)|[ \t]+([,!?;:])(?=\w)|([a-z][,!?;:])(?=\w))/gim,
            replacement: "$1$2 ",
            reason: App.consts.reasons.grammar
        },

The regex in the comma does identify the target commas, see the forked regex:

However when run using 1.5.2.38, none of those commas get replaced.