There is a need to bypass the queue when all members have DND set or are on the phone. in FreePBX this is Ultra Strict.
FreePBX rules on join and leave.
Yes – Determines if new callers will be admitted to the Queue, if not, the failover destination will be immediately pursued. The options include:Yes Always allows the caller to join the Queue. Strict – Same as Yes but more strict. Simply speaking, if no agent could answer the phone then don’t admit them. If agents are inuse or ringing someone else, caller will still be admitted. Ultra Strict – Same as Strict plus a queue member must be able to answer the phone ‘now’ to let them in. Simply speaking, any ‘available’ agents that could answer but are currently on the phone or ringing on behalf of another caller will be considered unavailable. No – Callers will not be admitted if all agents are paused, show an invalid state for their device, or have penalty values less than QUEUE_MAX_PENALTY Loose – Same as No except Callers will be admitted if there are paused agents who could become available.