Your problem is self inflicted, because you did not respect the rules for the Mp3tag scripting language.
On the basic scripting level, the round brackets are part of the scripting language and they are applied along with a function call to enclose the given parameter list for the called function.
Round brackets have to be devalued, when using them as literal characters.
A round bracket within a function parameter list has to be enclosed in single apostrophes, to make it a literal character, or simply enclose the entire parameter list in one pair of single apostrophes.
Maybe you can find some regex inspiration from there ... do have a closer look ...
Move "Featuring" from Artist to Title
DD.20170404.1031.CEST