RabbitMQ and SSL?

Question

Qt

There is a server, RabbitMQ is deployed. There is a client in Qt / C ++, it communicates with the server via the STOMP protocol (the client is semi-self-written, I did not want to pull the native bulky library of the AMQP protocol). The client connects to the server via SSL (so that the content of the transmitted data does not shine so much).
At the testing stage, while there were 1 - 5 clients, everything was fine. The connection is instant, the exchange is stable. We started a trial use on a larger scale, then misunderstandings began. The server is gaining about 60-70 connections (limit > 1000), then it drops the farthest. Clients are connected within 10-15 seconds,
After restarting the server, the same number is dialed again and plugged again.
I don’t understand where to dig, any ideas? Maybe someone came across.