Version: 64.0.3264.0
OS: Android
Architecture: <ARM, x64, etc.>

What steps will reproduce the problem?
1. Open facebook.com
2. In the Options Menu, hit "Desktop Site" 
3. Click at the "What are you thinking about?" Dialog Box
4. A popup window will the displayed
5. Type any word and press "space"
6. The text is erased with every hit of the "space" key

What is the expected output?
You could write a full text.

What do you see instead?
One can't type, because the text is automatically erased at each "space" 

Please use labels and text to provide additional information.