Apple Watch Activation Lock

Hello,

I recently sold my Apple Watch Series 2 online. I reset the watch and sent it. When the buyer received it, he said there was still and activation lock on it. I removed it from my iCloud account since, but he still claims it is there. I read a couple articles that stated that I had to unpair it from my phone before sending it, which I know I did. I also cannot access anything about it from my watch app. Since I have completed both of these steps, what should be done next to fix it?

Thank you.