WIth the current U26 the waypoint are very often broken and aren't at the doors but on the targets/locations. This has been a problem for quite while now, especially if you are using fast frames, that barely touch the floor, like Nova, Volt or Wukong. The last info I have about this is from january:   But U26 opened up this problem to the "slower" warframes, too. Now 1/3 of my missions are missing a propper waypoint.... (If you are playing for a while you know where the right