EdgeRouter X v1.9.0beta2 Load Balancing and telefonia Voip

Hi, I have a problem with the VoIP configuration with the load balancer. Currently my apparatus is configured with 3 internet connections from 15Mbit / 1.5Mbit and 1 8Mbit / 8Mbit symmetrical.
I configured the load balancer with the wizard and then created a LB Group Sip associating eth0 and eth1 only failover, I added a group ports from 5000 to 6200 so that all traffic intercepted with these ports will not be routed to 4 in eth A load balanced.
Everything seems to be working properly, after a about 3 -10 minutes and sometimes even after a 17-minute phone call voip phone loses its connection.
I made the same thing with traffic HTTPS port 443 to allow traffic to the websites of the banks and everything seems to work perfectly.
Enclose the configuration file.
Do you have any solution?