Connect/disconnect network causes all LDOMs to drop

Hello all, I am using latest OC 12.3.2 (co-located EC/PC).  I have started noticing that when connecting or disconnecting an LDOM to/from a network (ie. to add or remove a vnet), all the LDOMs that share the same virtual switch on that virtualization host are losing network connectivity.  The drop appears to be very brief - a running ping shows no packet loss however the logs show all IPMP groups failing during the job execution.

To summarize:

Virtualization host is running guest LDOMs A, B, C.  I want to add a new vnet (virtual NIC) to LDOM C:

1. Click on C's LDOM asset.