The standard QA check Unpaired Symbol is tuned to produce few false positives.
For certain kinds of translations, such as enclosing in parenthesis the source text, that follow special style guide conventions, we recommend using checklists instead.
For example, in your case, you could add checklists items like these:
Finds all segments that have both an open and close parenthesis in source and do not have both an open and close parenthesis in target.
Also, the following search:
where "tag" should be replaced by your tag text, will show all segments that have a certain source text enclosed in tags that does not appear in target enclosed in parentheses.