If the player declines (Let me prepare my ship) the meet stormhound mission (BenedictInNewBeyond / 04) they can be offered the mission from multiple stations.

This is due to maxAppearing only counting accepted missions (see issue 58310)

george moromisato 31 May 2018:

I fixes this in 1.8 Beta 2 by counting all created missions for purposes of maxAppearing. Thanks!