Can't add transitions to B roll later of Timeline?

I can't add transitions to the top layer above the main timeline. This seems to be a new issue since the last update --I used to be able to drag and drop transitions and it would go on the start and end of the clip. Also I used to be able to drag and drop a new transition over a transition I wanted to change on the main timeline and it would change...now, that doesn't work anymore either. What is going on? Is there a setting I can change or is the new update the cause of this? I have a video screen grab that I can share a link to, if none of this makes sense.