JWT with no subject?

Hello!

I am using webhooks, defined in the app descriptor to catch some events happening in Jira. Although it seems easy and everything works fine for most of the events, I have encountered an issue with the user events. I can determine the host based on the JWT coming from the request (using the Authorization parameter) for the issue events, but I cannot do that for the user events. From my investigations, it looks like the JWT for the user_created, user_updated and user_deleted events do not contain the subject while the ones for the issue events do have it, as you can see in the image below, where the first picture is for a issue comment edited event and the second one is for an user deleted event.
Could this be possible? Do you have any idea why this would happen? Thank you!