Ahoi!
When i had this issue in the past, i loaded an earlier save from the past and shiped again to the harbour. When then the anchor icon doesnt appear, i saved again and load the last save, like you also did. Again, the solution was to load another save which was at least 150 km (or was it 50km iam not sure..better use the 150km range) away from the harbour. Then it works.. i had this bug more then once in all the years, so relax and try what iam telling you now.
