Insurers Chubb, AIG, Travelers and others are dealing with a return to work headache: A rising number of lawsuits against employers. The costs, settlements and verdicts will affect insurers' bottom lines. For business, they're potential pitfalls when trying to enter the post-pandemic era. CNBC's Contessa Brewer walks through the risks employers face as they navigate vaccines, health and safety and requests for continued work from home.