Not necessarily.
Why do you say not necessarily when the U.S.C. says it does?
Objections
Since 1887, 3 U.S.C. 15 has set the method for objections by Members of Congress to electoral votes. During the Joint Session, lawmakers may object to individual electoral votes or to state returns as a whole. An objection must be declared in writing and signed by at least one Representative and one Senator. In the case of an objection, the Joint Session recesses and each chamber considers the objection separately for no more than two hours; each Member may speak for five minutes or less. After each house votes on whether to accept the objection, the Joint Session reconvenes and both chambers disclose their decisions. If both chambers agree to the objection, the electoral votes in question are not counted. If either chamber opposes the objection, the votes are counted. Objections to the Electoral College votes were recorded in 1969 and 2005. In both cases, the House and Senate rejected the objections and the votes in question were counted.