Asterisk, Sipml5, WebRTC. Is it possible to simultaneously call n-th number of clients through one WebRTC extension?

Question

Asterisk

Good day to all! There is a very non-standard situation in Asterisk.
The essence of the problem is as follows: calls from webRTC to Asterisk .
What we have:

1) There is a configured Asterisk.
2) There is a configured WebRTC.
3) Calls are made with doubango.

Description of the problem:
I need to set up calls from the site, everything already works correctly for me, except for one.
When making a call with doubango , two customers and two operators are connected at once.
How it happens
, we have doubango in which one user registers, then another user logs in from another computer, then a call is made from one user and another user from another computer, (operators have not yet received calls from their users) it turns out that the operator accepts the call of one client, then another operator receives a call from another client and they all hear each other (it turned out to be a conference with several users ), it turns out a mess (clients who should not hear each other participate in one stream ).
Of course, one exstention is configured to call operators.
( I don’t think they need more if it works correctly after the client has called and is already on the line with the operator )
In principle, everything works fine when the first client logged in and got in touch with the operator, then the second client, having logged in, can contact the operator without problems.
As I understand it, when dialing to Asterisk, users do not have a common bridge, after the connection a bridge is formed, one for four people, two clients and two operators.
Essence of the question:
Is it possible to configure Asterisk in such a way that there would not be such a mess when simultaneously calling from clients via WebRTC, or is it still better to connect clients after one of the operators has already connected to the client?