Stage is not visible on Preview or LiveApp after a row is added at the top of canvas

I created a new project and added a Canvas. The sprites were visible until I added a row at the top. I added a border to the canvas and I can see it in preview. I changed the background of the Stage but I don’t see it so I think the problem is with the stage. I even added a new Stage but the problem persists. And once this happens it is the same behavior even if I add any new screens or Canvas. I have to create a whole new project from scratch and start again. Is this a known bug in Thunkable. I spend so much time restarting my projects by creating new ones. It is frustrating. And I am not getting responses from support. I have the Pro membership.