When entering a portal that is close to an entrance to a weavers tomb the character tries going through both of them, and you get teleported out to monolith selection without getting the echo completion rewards. Likely due to the game teleporting you to the reward section but then tries to teleport you into the tomb, but being unable to do so , sends you into the timeline selection. May be a thing specific to WASD movement interracting with LMB to interract. This has happenned to me at least 5 times or so.
Managed to easily replicate it in the video.