DTMF Event Forwarding delayed

Hello all,
I have turned DTMF event forwarding on, but when I am in a conference call, when one node sends a DTMF event it can be up to 3 seconds before the event is actually delivered to the other endpoints by Asterisk. Asterisk seems to be ‘holding on’ to the event for several seconds.

Any ideas?

Which conferencing application? Which Asterisk version?

confbridge, 10.4. Am currently loading 10.6 to see if it happens there.