Topic: Using "screen" back button removes bottom right add button.
After looking up my campaign in app, I pressed the on-screen back button (located on top of screen) to add more campaigns.
I could not find the circular add button.
I backed all the way out to the main screen, went back into dm tools and opened up campaigns; the circular add button returned.
NOTE: Add button remains when using the device back button (located at bottom of screen)