L2switch scalability issues

I have tried several scalability tests with odl-l2switch-switch-ui feature installed. When I increase the number of switches in the topology using mininet tree,6 (63) or tree,7 (127) it is very normal to miss flood flows in some of the switches (LLDP flows are fine). With cluster feature enabled (odl-mdsal-clustering), I can see missing flows even with small topologies like mininet tree,4 (15) and tree,5 (31)

Openflow topology, inventory and stats seem to work fine in these mininet topologies so thats why I think the issue could be in the l2swich application.

BR/Luis