LACP members dropping on Solaris 11 11/11 SPARC

T4-4's and T4-1's.  All using 4 x 10gbe links aggregated into one port channel across two Nexus 5ks.  After heavy traffic the links drop out of the LACP aggregation and go into "DEFAULTED".  Eventually all 4 will drop and will not come back until a reboot of the global.

Any insight would be appreciated.

When the state is healthy it looks like this:

 dladm show-aggr -L
LINK PORT AGGREGATABLE SYNC COLL DIST DEFAULTED EXPIRED
aggr1 net6 yes yes yes yes no no
-- net7 yes yes yes yes no no
-- net4 yes yes yes yes no no