"If I ignore harassment, it will go away" … is the 100% incorrect response to harassment happening in your workplace. It's also a non-refundable first-class ticket to a nasty lawsuit.
An employer CANNOT ostrich workplace protected class harassment. "Employer" includes managers and supervisors. If someone in a position of authority witnesses or otherwise learns of protected class harassment in the workplace, the business has the same legal obligations as if the victim had complained.
2.) Investigate, promptly and fully.
3.) Evaluate the evidence and make a reasoned conclusion as to what happened.
4.) Correct the harassment with prompt and effective remedial steps, if necessary.
5.) Retrain all employees about your anti-harassment policy to help prevent future harassment.
6.) Never retaliate. Ever!
Under no circumstances can you, as an employer, ignore harassment that you know about or should know about. It is not a defense for you to bury your organizational head in the sand and hope that it will all be gone when you emerge into the sunlight. If opt for the “ostrich,” all you will see after shaking the sand off your face is an expensive (and indefensible?) harassment lawsuit.