Case of counterfeiting patented technology

Has the patent expired 10 years? It doesn't matter if it expires, the patent still exists, and the patent is still yours. This is not in the patent law. It can still be produced after it expires. This is not a counterfeit product. But it depends on the specific situation. What is the reason for the expiration? What is the reason for the buyer to sue you? Wait a minute. Ask a lawyer for advice.