Since 2.0, the game throws me back at the main menu after aventure maps, but now it also does this to me in weave : after reaching the portal at the end of the first part of the weave, the game send me to the main menu during the loading screen between the two part of the weave.
This happens to me as host as well as not host and seem random if it happens or not, sometimes it is everytime, sometimes I can many games without this happening.