"To contest this issue" means to challenge or dispute something, usually in a formal way, in order to prove that it is wrong or incorrect. Full definition
Child custody can become one of the most hotly contested issues in a couple's breakup. (info.legalzoom.com)
So it really should come as no surprise that outside of child custody, financial matters are typically the most highly contested issues in a divorce. (capps-law.com)
However, because the collaborative attorneys will not bring contested issues to court, their focus is on finding solutions rather than using the meetings as a tool of opposition research. (familydiplomacy.com)