Help! Asterisk wont record dynamic queue calls

MixMonitor consuming resources

queue type: dynamic
(sip extensions can log in as agents)

queues.conf

[queuename]
monitor-type = MixMonitor
monitor-format = wav
monitor-join = yes

agents.conf

[agents]
recordagencalls=yes
monitor-join = yes
recordformat=wav
savecallsin=/var/spool/asterisk/monitor

extensions.conf

exten => 6509,1,answer

exten => 6509,n,Set(MONITOR_FILENAME=${TIMESTAMP}-${CALLERIDNUM}-${UNIQUEID})

How to compell it to work?