Add Text Box/Text Callout - Unable to edit text properties (greyed out)

I'm using Adobe Acrobat DC (v 15.017.20050).

I tried to insert text box and text callout - I had successfully been able to edit text before but for the past week I am unable to edit the properties of text in both command.

The box properties itself still working

Please let me know how to fix this issue. I tried uninstalling and reinstall and it works only the first time then the problem persists.

Thank you very much,

Papon