Lorient doesn't become available as a player base until Sep 1940.
My guess is you received the message "U 30, 52, 34, 99: Report to the port of Lorient.", which is broadcast on 5 July 1940 and is really just ear candy - albeit confusing if you happen to be in U-30, 52, 34 or 99.
Alternatively you may have received "U-99: New orders as assigned: Arrive 50 miles West off Lorient." or even "A new submarine base is available for operations in Lorient." which are both broadcast in July. Again, "ear candy" only messages.
At midnight on 1 Sep 1940 you will get a distinct "Player base changed to Lorient" message (of course, this is 2 Flotilla only).