I have no experience with that technology, however do you have the latest version?
Starting with Junos OS Release 14.2R3 on MX Series routers, enhanced convergence improves Layer 2 and Layer 3 convergence time when a multichassis aggregated Ethernet (MC-AE) link goes down or comes up in a bridge domain or VLAN. Convergence time is improved because the traffic on the MC-AE interface is switched to the interchassis link (ICL) without waiting for a MAC address update.
If you have configured an IRB interface over an MC-AE interface that has enhanced convergences enabled, then you must configure enhanced convergence on the IRB interface as well. Enhanced convergence must be enabled for both Layer 2 and Layer 3 interfaces.