Some interactivity buttons created in Adobe Captivate are not displayed in the browser.How to be
Please, provide some more details, this is a very vague question.
All buttons are interactive objects. If some do not appear, that can be due to a timeline issue, but to many other causes. It is also good to know which version of Captivate you are using (full version number), which OS, if you are talking about a non-responsive or a responsive project. If it is a responsive project, which workflow: Fluid Boxes or Breakpoint Views?
How did you test: I see 'in browser' but is that after publishing or during Preview?