I repaired the pipeline under PTS 5.x in Alaska in North Port and then I went through the Mountain River map (without open a watchtower or do a task) to the White Valley garage. In White Valley, too, without opening a watchtower or completing a task. These two cards are closed again.
Screenshot before entering portal to White Valley (White Valley is closed):
Screenshot after the portal (my way under PTS 5.x to the garage is visible, but map was closed):
In Smithville Dam I opened a watchtower and do the task at the garage to clear the way. This map was correct open. Looks like it's a problem with the maps where no task was done.
Possible, that this happened at the update 6.0 to 6.1. I can remember that I looked under 6.0 to the task at the long bridge in White Valley. This means, that I was at the garage in White Valley under 6.0 and now I have (had) no access to the garage. And the tasks on both bridges have disappeared again. I started the tasks as I drove past.