So, I followed the video by Shaun Spalding on live room editing and also followed the "cheat sheet" here and have double checked that I have followed all the steps correctly, but live room editing for me does not seem to work. I put a colored rectangle on the asset layer of a room and then tried to drag and make it bigger/smaller, but the change is not reflected in real time in GM.
On the other hand, live update of draw events have been working as intended for me.