Conference room limit to 2 users?

i set up a conference room on wazo 17.03.
Everything works fine but with a limitation.

The third external participant comes across a message indicating that the correspondent is not available.

however the conference room authorizes is set to 10 users and it works well with many users in internal.

is there a setting for the number of simultaneous external incoming calls on a number

any idea ?

If the caller is dialing an external number, I would check the limitation from the incoming trunk (in Wazo : Interconnection --> SIP protocol), and also on the SIP provider side.

There is no limitation by the software for the conference room.