I came across a fun little issue with JetPack. If you install JetPack on one domain (such as a development site) and them move the database and files to another domain (production), plus change the domain via MySQL, JetPack continues to work off the original domain.

Your users will get comment notifications from the original domain and JetPack will send users back to the original domain if they are subscribed via WordPress.com.

To fix this, you need to disconnect JetPack and reconnect it on the new domain.

It’s very easy, but can be a big mess if you don’t realize it’s happening; which you won’t as JetPack continues to work great.

According to the JetPack GitHub, it’s not really a bug. If you change the domain in WordPress’ settings, then it should be fine. If you do it via MySQL, then the issue is created.