Master portal disappears after leaving hideout

I started a daily mission at Vagan and was waiting for a friend to join my hideout. Because he was busy, I decided to look for some decorations at masters that I don't have in my hideout. When I came back (only a minute later), Vagan was back at my hideout and the portal was gone. When I talked to Vagan I couldn't start the daily mission anymore, it was saying I already did the daily mission. But neither I or my friend even used the portal to enter the area. I assumed the portal would still be there, since self cast portals normaly stay open for as long an instance is active. But I can understand this works a little different for a daily mission or a hideout. But shouldn't u then get a warning when u leave the hideout or be able to restart the daily mission if u haven't entered the portal?