Has the format of event subscription messages changed?

The event subscription reception logic using websocket that I created about 1 year ago is not working at all.

I looked at the source code. Then, it is assumed that the notification message has the following format.

=================

{

'content':{JWT-value},

'time':'12/10/2022 01:41:36'

}

=================

And I remember actually receiving a message like this.

However, the message currently flowing looks like the following.

=================

{JWT-value}

=================

Did the format change at some point?

Will there be no changes like this in the future?

Has anything else changed?