Problem with queues kicking out agents


I have a couple of queues that I’m having problems with.
Some of my agents are getting kicked out from the queues randomly.
I suspect that this is because the channel sometimes becomes UNAVAILABLE.
I have some settings that should prevent that:

autologoff = 10000
autologoffunavail = no


timeoutrestart = yes
timeout = 15
autopause = no
memberdelay = 2

I’m using Asterisk

Any idea why this is happening?
Am I missing any setting somewhere?

This is the CLI output regarding this problem.
It happens imidiatelly after the agent logs in:

-- Executing [*2020@from-internal-queues:1] AgentCallbackLogin("SIP/94450-b7012688", "94450||94450@from-internal-queues") in new stack
-- <SIP/94450-b7012688> Playing 'agent-pass' (language 'en')

== Setting global variable ‘AGENTBYCALLERID_94450’ to ‘94450’
– <SIP/94450-b7012688> Playing ‘agent-loginok’ (language ‘en’)
– outgoing agentcall, to agent ‘94450’, on ‘Local/94450@from-internal-queues-2bb0,1’
– Executing [94450@from-internal-queues:1] Dial(“Local/94450@from-internal-queues-2bb0,2”, “SIP/94450|60|t”) in new stack
– Called 94450
– Got SIP response 486 “Busy” back from XXX.XXX.XXX.XXX
– SIP/94450-08e76738 is busy
== Everyone is busy/congested at this time (1:1/0/0)
== Auto fallthrough, channel ‘Local/94450@from-internal-queues-2bb0,2’ status is ‘BUSY’
– Agent/94450 is busy
– Nobody picked up in 0 ms
== Callback Agent ‘94450’ logged out

Any idea why is this happening?