Driver NAT/NAL Update Through Agents

I am trying to update driver NAT/NALs using agent actions. I can insert a new manual NAT/NAL into the driver_assignment table. Unfortunately, even though I insert a new sequence number, OTM throws an error on all future driver assignments saying that the sequence number is not unique.

I looked in the bn_sequence table and do not see an entry for the driver_assignment table that can be updated. Does anybody know what can be done to fix this?