That is correct, this queue is experiencing strange behaviors like calls going missing in logs and not being recorded like 1% of the time. it looks like. This queue is the only one setup like this and not sure if this is causing issues with 3CX "Freaking" out trying to track this call that has 1000's of polling requests on it.Its likely set to "ring mobile simultaneously" which keeps the agent alive. Unfortunately, 3CX isnt designed to keep a queue open without anyone present, this is the only way to keep it open.
Founded in 2005, when VoIP was an emerging technology, 3CX has gone on to establish itself as a global leader in business communications.