Send Event Task with RabbitMQ - Multi-instance type parallel

I have proces with Collapsed sub process which work as parallel multi-instance type with async flag.

Inside I have subprocess with Send Event Task with RabbitMQ

Collapsed Sub Process run parallel with List which contains some data. The problem is when list contains more than one element. Only one message is published on queue. When list contains three elements and more, it publishes two elements (even if list contains 10 elements)
I put listener on send task with rabbitmq and this task starts as many times as it should, list size. Unfortunately queue does not get messages.
Logs show that messages were not published. No error

Any ideas what is wrong? Queue config? Async flag?

What is interesting, when I reload database. Delete all data and boot up again. Problem does not occur. Any idea what can cause this situation?