I did some more testing.
The agents are logging into the queue using the FreePBX feature code. I noticed it is putting them into the queue as a local channel(Local/299@from-queue/n). When they transfer calls, it is not appearing in the queue_log.
On the CLI, I added an agent to the queue using their extension number.(ex. queue add member PJSIP/299 to 490). The blind transfer event is appearing in the queue_log.
That actually makes perfect sense. There are at least five different channel drivers on my system; the number on yours should be close to that. To avoid a lot of redundancy, most of the code would be (or at least, should be) written to use the Local channel alias so that it’s mapped by just the extension.
In the case of Local channels with /n, you aren’t transferring the caller in the queue. It may appear that way to the caller but it’s not what is happening. They remain in the queue, they’re just connected elsewhere.