Im not a specialist too, just trying to help the new ones like me.
FreePBX has the tab Settings in the upper part, under which you will find General Settings.
If you got the queue already running, the device you are dialing should have an extension, you could add that extension in the queue agents box, so whenever anything is routed to the queue, it will ring the agents in it.
Then you will need an inbound route to associate that queue with a DID, so whenever you call the DID, it will route the call to the queue, which will call the agents.
Since queue ring times doesn’t depend on extensions ring time, this could solve your ringing shortage.
But I will still check the General Settings default ring time value.
Regards.