Reject incoming calls from Asterisk websockets in the browser. What could be the reason?

Question

Asterisk

There is a web interface for processing incoming calls. A web socket call comes in from Asterisk and the handset starts ringing in the browser. When you try to answer, the connection fails. I start looking at what is happening on the equipment, and there is such a trace prntscr.com/fv8ebu It turns out that 4,5,7,18,20 is 5 calls. I tried to replace the browser with media5-fone, the situation does not change on the asterisk, and already missed calls come to the application.

How to make it so that there is only one invite to which you can answer?
Thanks in advance.