I encountered some strange behavior in challenge mode when you save any group of objects to a blueprint and check the "Set Custom Hour" checkbox. Whatever time you set it to in this will lock the time in the actual game. For a couple days now I've been wondering where my Day/Night cycle had gone and it turns out I accidentally disabled it around when I started when saving a new building I made to a blueprint. Just now I went on a hunch and realized what had happened and got my day/night cycle back by unchecking the box.
Another thing I've noticed is a really irritating bug regarding barriers of any kind. Barriers become completely unremovable seemingly at random and no amount of attempting to delete them will work unless the segment isn't part of a habitat and you have a delete button on screen to click. I have a hunch this may have something to do with the barriers research but I can't confirm. Reloading the save fixes the issue.
Hopefully these things can be addressed in a future patch.
Another thing I've noticed is a really irritating bug regarding barriers of any kind. Barriers become completely unremovable seemingly at random and no amount of attempting to delete them will work unless the segment isn't part of a habitat and you have a delete button on screen to click. I have a hunch this may have something to do with the barriers research but I can't confirm. Reloading the save fixes the issue.
Hopefully these things can be addressed in a future patch.