My Activity Stream - Input box and Post button not showing on mobile

On any mobile or Tablet screen - less than width of 980px, Post button and Input Field of “My Activity Stream” vanishes.
Please help me to resolve this issue.

I was able to reproduce this on the live demo. Please open an Issue for this on GitHub so the developers can look at it.

Thanks for reporting.

https://github.com/salesagility/SuiteCRM/issues