[US] Is this scam? My employer sent me cashier check and I verified with bank which issued the check came as invalid.

I had worked for the company and now last week was my payday. They told me first pay I get would be in cashier’s check. I thought ok. I guest for security they might do first pay in check. Anyway, I received a cashier’s check from them on Friday evening. And on Monday morning i decided to call the bank on the check to get it verified and they told me it’s invalid. I called my boss and told them that I can’t cash it. He told me why can’t? I just told him they told me I can’t cash it. He told me ok go to credit union near your house with utility bill and sign it back of the check and try to cash it at credit union. Should I report my company and my boss to ftc and police? Should I quit and assume my work hours earned money is gone??

I did not put the company name or my boss name here for security reason just need advice what should I do? I am going to report it to FTC and local police but should I quit before doing so?