We are having problem with the new UI and when having a lot of different items in our custom menu. I replicated it so you can see (so, this not how our looks just for you to see what is happening) in the image below. As you can see part of Visitor Groups is gone and if there were any items on the right of it, they would not be possible to select.
Are there any way to fix so it can be scrollable or simular?